The 260SX Sound Enhancements
Welcome to the part of our webpage devoted strictly to highlighting, in the greatest detail possible, the one-of-a-kind high performance audio system in the 260SX. In our unabashed opinion, the audio work done in this vehicle is as close as you can get to complete mechanical and electrical optimization in a mobile audio environment. Everything that could have been done, was done. There was no expense spared in this build-up. There was no proven technique that was not incorporated into the design. Nothing was "held back" because of time constraints (there honestly never were any time constraints). There was no such thing as "the law of diminishing returns" in this project. If we perceived that a sonic benefit could be made by embarking on a scope of work, we did it, without hesitation. This audio system represents, by far, our greatest achievement.
BACKGROUND
First a little background. Our "claim to fame" is super high-end car audio. It's fun to watch the hardcore performance and styling guys look at the vehicle (and try and pronounce "Buwalda" in Buwalda Hybrids). It's also fun to hear how stereo systems have no place in a performance car. We disagree. The perfect show and competition vehicle is an equal mixture of the three elements that make an excellent show vehicle, not just one or two. In our unabashed opinion, this is the most complete "three S" (Speed, Style, and Sound) vehicle on any show or competition circuit. We kept weight to a minimum, and pushed the limits of high-end audio all at the same time.
While the car you see on these pages fully embodies the philosophy of "Speed, Style, and Sound", our true passion is Sound. Scott Buwalda, the owner and lead installer of the project, has been building and competing cars since 1987 (first competition was Spring 1988, a Car Audio Nationals Prelims. II event in Jupiter, Florida), so it was only natural to build yet another championship-caliber car stereo vehicle, this time with a few "twists." Not only that, but this vehicle is sponsored by Hybrid Audio Technologies, and is used as their lead demonstration vehicle...and if we can figure out the new rules structure and convince them to bring back REAL creativity, and not some watered down version of "system enhancements" (like points for sound damping??), we'll compete it. This is easily a 100+ point creativity car by the old IASCA rulebook, so we eagerly await to see how the 2006 season goes, and the tweaks they (namely IASCA) make to the score sheets, specifically as it relates to real system design creativity. It's our opinion that expert vehicles should be allowed to compete on an expert level, and there should be UNLIMITED CREATIVITY, and more sound quality points available for things like musical realism.
The original design goal of this vehicle was to build a very fast, great looking sound quality competition vehicle. Little has changed in this original design philosophy since its inception. The old Expert 240SX competition car had an outrageous audio system, but was admittedly light on styling, and VERY light on performance (typical bolt-on's are NOT performance). This car was great for the audio guys, but the hardcore performance guys saw the additional weight and lack of power, and immediately dismissed the vehicle, even though there was thousands of hours of custom labor. With the 260SX Project, however, the performance and styling guys enjoy the vehicle as much as the audio guys. This makes a perfect platform for the proliferation of our Hybrid Audio brand name, the international campaign of this vehicle in media---print, on-line, radio, and television, and the exposure of our sponsors.
One final note about this vehicle's audio system enhancements. There is a lot of "over the top stuff" in this car, and no write-up could really ever do it all justice. You just need to come see the car in person, sit down and have a listen, and take it all in. Those that try and judge this car by looking at a few pictures are very seriously misinformed. And beware of what lurks underneath OEM looking, vinyl-covered panels. We'll give the audio system enhancements write-up our best effort, but realize that you really just need to see and hear the car in person. Additionally, there's some proprietary technologies and installation techniques in this vehicle, and we'll do our best to give you the "gist" of what we did, and/or the system's adaptive technologies and installation techniques, but it only makes sense to not reveal too much, and chalk a few of these ideas up to "trade secrets." Don't worry, you're going to get 99% of the vehicle, it's just the last 1% is something we're going to guard a little more closely. Besides, a little mystery in a vehicle ads to its mystique. :-)
DESIGN PHILOSOPHY
The design philosophy for the audio system was quite simple: electrical and mechanical optimization of the listening space. We have found that, at a certain point in any high-end build-up, you begin to reach the point of diminishing returns. Most designers and installers see the reverse asymptotic curve of diminishing return, and quit with a good audio system that sounds, well, "good." Some guys start the trek up the curve and manage to create a car that sounds "really good." Then there are a select few, however, that really make a science of pushing the technique up the diminishing returns curve, and usually make great gains in mechanical optimization. We are part of this fanatical fringe, but are proud to say that we've made equally exciting gains in the electrical optimization realm in just the same way. The 260SX vehicle is an application, a science project if you will, at complete mechanical and electrical optimization. When asked what we mean exactly, our typical response is "anything that could have been done to improve the playback experience, we did it in this car." To make the car better we'd have to remove windows, which isn't exactly in the cards when doing low 10-second passes on the 1320 or drifting at 80 MPH. So without sounding conceited, we feel fairly confident that this is about as far as you can take a car in both electrical and mechanical optimization. Let's dig in and dissect the vehicle now...
SYSTEM OVERVIEW
The audio system is incredibly basic as far as componentry is concerned (the real complicated parts come from how the components were installed, where they were installed, and what's inside the electronic components). Here is a basic system diagram:
SYSTEM DESIGN
Perhaps the best way to go about doing a full system design explanation is to start from the very beginning, and describe what was done to the vehicle in order of chronology.
Tear Down!
In October of 2002, the original Expert 240SX sound competition vehicle was officially retired, and every part that could be disassembled from the car was removed, and sold on various online car audio forums, as well as eBay. What was left at the end of the massive dismantling project was nothing more than a frame situated on four jack stands. The joke around the shop was “anything that could be unbolted was unbolted from the car”, leaving only parts that couldn't be removed from the frame structure of the vehicle. It is no secret now that the original competition car frame from the Expert 240SX was used as the basis for this vehicle project, so much was required to bring the vehicle to a condition so that a super high-end installation could be performed on a “clean slate.” What we really needed was a brand new chassis to ensure the magnitude of the proposed project could be carried out in complete form, so we set out to adapt the existing chassis to make it amenable to the next, and final iteration of this S14 project.
Once the car was completely disassembled, all of the sound damping materials that had been installed in the vehicle over the years were removed, as well as all of the original equipment manufacturer sound damping products, such as those pesky asphaltic-based damping pads located on the floor of this vehicle. One of the more laborious projects was removing all of the spray-on the sound damping materials that had been applied to the rearward portion of the passenger compartment in approximately 1997 (even Buwalda used to be a part of the latest car audio "trend!"). All of this sound damping was physically removed using a pneumatic air grinder attached to various surface preparation wheels to bring the car frame and interior body panles back to the point of fresh metal without any form of paint, or sound damping material. The original equipment manufacturer asphaltic-based sound damping was cleverly removed by using bagged dry ice, and allowing the dry ice to super cool the asphaltic-based damping, making it brittle and easy to remove from the vehicle.
Frame and Body Panel Welding
Once the entire in interior of the vehicle was brought back to a condition of being bear, stripped metal, it was noted that there were several hundred holes in the vehicle's chassis. These holes ranged in size from a mere screw hole to holes larger than 1 inch in diameter. The holes were a result of the manufacturing of the vehicle, former wire routing holes, wire channeling holes and "Christmas tree" holes, and several holes cut into the metal during various iterations of the installation projects in this vehicle (8 years worth). Using a wire feed welder, all of these holes were sealed shut to ensure that the chassis was complete and “one solid piece of metal” prior to the initiation of new installation activities. What might seem to be an easy exercise in chassis cleanup, sorting out the details of a high-end installation before the installation actually physically began, turned out to be an extremely laborious process comprising of approximately 6 weeks of labor to remove all of the old materials and paint, and to ensure that the car was ready for an installation of this caliber.
Catalyzed Protective Substrate
With the original sound damping materials being removed, all of the interior body panels treated and all ancillary holes being welded shut, we opted for a unique strategy to complete the process of improving the car's chassis. We decided that a fresh coat of a protective substrate be sprayed onto the entire chassis. It was decided that we would spray a catalyzed mixture of truck bed coating to treat the entire interior of the vehicle, to give a consistent look and texture to the interior body panels, as well as to thwart the potential for oxidation and rust in the exposed metal surfaces. The catalyzed truck coating was applied by a local speed shop; we found early on in the exercise that the products that can be purchased at the local auto supply store are not nearly as good, nor as effective as the professional grade catalyzed coating available through professional purveyors. Once the catalyzed truck bed coating was sprayed throughout the entire interior of the vehicle, work was resumed to continue the installation process.
Sound Damping - Application of B-Quiet
The next order of business was installing a double layer of B-Quiet sheet-style sound damping material in all of the areas forward of the seated area. Doing a good job with sound damping is easy when the car is completely stripped of all interior and cosmetic trim panels. Once complete, a layer of B-Quiet laminated decoupling compound was installed above the recently damped area, to ensure that nuisance vibrations and resonances from the kick panel-mounted subwoofers would not interfere with the listening experience. Just prior to doing all of the sound damping work near the future front stage location, all of the welding and fabrication that was required to ensure optimized placement of the midrange and tweeter drivers in the former windshield wiper cowl area was performed. We would love to tell you more about what exactly we did in this area, but alas, this is one of the car's trade secrets and its best to just leave it a secret for now (we have been burned in the past with judges knowing too much about a front stage and have learned our lesson -- use non-removable grills and don't discuss how the front stage is arranged, crossover frequencies, etc.). Sorry, there is just too much at stake here to give away all of the secrets like we did for the last vehicle! We will, however, give a couple of clues later on in this right up!
Electrical System
Once all of the welding and sound damping removal activities had been completed on the vehicle, the layout of the new installation was begun. We quickly knew that the battery would need to go in the rear portion of the vehicle, as there was no room for the battery under the hood (given the large engine swap and intercooler piping required to run where the battery would be mounted in a typical installation). So the first order of business was to weld in a strut tower brace between the rear strut assembly in the vehicle. A heavy gauge metal battery mounting structure was recycled from the original installation, and was welded to the strut tower brace. We also needed a spot for the PowerMaxx alternator diode pack assembly to be located near the battery, so brackets were also installed between the strut tower brace and the chassis of the vehicle to accommodate for the installation of the diode pack. Before long, products began to be populated to be test fitted into the metal structures in the rearward portion of the vehicle. An Optima blue top battery was installed in the welded steel cage, located immediately above the differential case in the trunk compartment. The steel battery cage included welded tabs which self align the battery into the cage using the battery's original carrying handle channels. The battery was slid in place and IXOS 1/0-gauge power and ground wires were connected to the IXOS battery terminals. All of the 1/0-gauge power and ground wires were neatly and securely protected with Techflex expandable nylon tubing. Additionally all of the terminations were neatly protected with black heat shrink and black nylon wire ties secured at regular intervals to ensure wiring cosmetics and wiring integrity were completed with the greatest amount of detail. The car looks just as just with all of the cosmetic panels remeoved. The main grounding point of the vehicle was established on the passenger side rear strut tower, an area of structural metal to ensure an adequate grounding point. A secondary grounding point was established directly to the car's frame immediately beneath the battery mounting area. A single 1/0-gauge IXOS power wire was routed from the positive terminal of the battery to the diode pack assembly, which was mounted approximately 8 inches to the right of the battery (it's like having the alternator eight inches from the battery). Finally a single 1/0-gauge power wire was routed down to the eventual placement of the large distribution block immediately beneath the battery location, visible from the seated position inside the vehicle.
Fuel Cell Platform
Moving into the trunk compartment area, a pair of 1 inch tubular steel frames were welded in the spare tire well of the trunk, to accommodate the eventual installation of a fuel cell in this area. One of the first things that was done for safety's sake was to remove the original equipment manufacturer fuel tank, located immediately beneath the battery and fuse distribution area located in the trunk area. Not only that, but the original fuel lines and fuel pump would not support the horsepower requirements of the new engine assembly, and a new fuel system comprising of a fuel cell, outboard fuel pump, and extremely large fuel lines would need to be installed. Once the tubular steel was welded to the spare tire well of the trunk area, a 7-gallon fuel cell was installed using security hardware.
Liquid Cooling and Pneumatics System
Other functional considerations were also performed in the trunk area in concert with the installation of the fuel cell, including the installation of a liquid cooling reservoir on the left side of the trunk, and a liquid cooling radiator on the right side of the trunk. Both the liquid cooling reservoir and the liquid cooling radiator were attached to the vehicle using machined aluminum brackets painted black to be cosmetically consistent with the installation. A significant level of effort was afforded to the installation of both the reservoir and the radiator, to ensure that they were in exactly identical, mirror image locations in the vehicle's trunk area to ensure that the future trim panel would be consistent from left to right. Once these two products were installed, a level of effort was given to the installation of a pneumatic compression system in the vehicle's trunk to allow for the use of pneumatic cylinders to assist in motorization capabilities (to be discussed later). A two-liter storage tank was installed on a custom bracket assembly which was welded to the car’s inner fender well located in the left side of the trunk. Located immediately beneath the air storage tank, we installed a quiet, yet powerful air compressor. Like the other products installed in the trunk area, the air compressor was attached to steel brackets which were welded to the car's frame rail, an area located along the trunk floor with significant structural support. Located immediately next to the air compressor is a water pump, to allow for the circulation of liquid to be pumped through the reservoir to the liquid cooling radiator and associated cooling fans, and up to the bank of four large amplifiers to be eventually located in passenger compartment. All of the plumbing was preliminarily routed between the liquid cooling pump, the liquid cooling reservoir, and the liquid cooling radiator, with piping left unterminated for now into the rear deck area, for even actual connection to the amplifiers. We used 5/8" polyethylene tubing for all of our plumbing in the trunk area, to ensure an adequate volume of liquid cooling material to the various parts of the system, as well as to the amplifiers.
Prior to moving on to other aspects of the insulation, all of the electrical wiring required to be completed for the liquid cooling system, and the pneumatic system was routed to the eventual location of the main system fuse area and the computer circuitry area located in the former backseat area. All of the wiring was routed using IXOS 6-conductor wiring to ensure ease of serviceability and upgradability in the future. A complete 500-foot roll of IXOS 6-conductor cable would eventually be used in the installation, in both aftermarket and OEM applications; it is estimated that there is more than 4,000 feet of copper wire, not including wiring related to the audio system in this vehicle. More details on why we needed so much cable are coming later on in this discussion (we will give you a hint though: it has to do with the fact that the entire car and all of its functions and remote sensing devices are controlled via onboard computer).
At this point in the installation the battery, diode pack, and all associated wiring had been completed for the charging system, including a single 1/0-gauge IXOS wire, protected in Techflex tubing, to the front of the vehicle for eventual connection to the starter solenoid. The trunk was beginning to take shape, with the installation of the air pneumatic system, the liquid cooling system, all associated hardware and plumbing, and the inclusion of a fuel cell in the floor of the trunk. We began to consider the placement of the amplifiers now.
Rear Glass Motorization
About this time, a good friend by the name of Chris Bakay came by to visit us and view the project prior to leaving for a new job in Boston (mid 2004). We were lamenting to him how we didn't know where to put the amplifiers. The original concept called for placement of the amplifiers in a similar fashion to the old installation, which would have placed the amplifiers immediately forward of the battery area between the battery and the front seats. A second option was discussed which included the installation of the amplifiers from the ceiling down to the shock towers. But there was also some concern over the ability of showing them off appropriately. Chris came up with a good idea of removing the back window and motorizing it up and down to expose the internals of the amplifiers. What started out as a joke quickly became reality as this crazy idea went from nothing more than just a good friend dropping an almost unattainable concept onto the installation crew just before leaving town, to reality within a few days of time.
Measurements were taken of the rear window area as well as the available space between the strut towers, and it was determined that four of the amplifiers would fit side-by-side with some creative stacking, with approximate 1/8" to spare between the strut towers! The rear window was immediately removed from the car and mold release compound was spread in a healthy layer over the entire window assembly. A positive mold was pulled off of the window using two thick layers of marine grade, 22-ounce fiberglass; this is the thickness of fiberglass that boat manufacturers use to build boat hulls. Almost 2 gallons of resin were used to ensure that the window was a consistent thickness to the original glass window, would ensure rigidity under motorized conditions, and could be made to look like a real window with some creative painting and airbrushing. Within a few days, there was a completely fiberglass replica of an OEM Nissan S14 back window in the shop, sprayed with 2K primer, and sanded to perfection to 500-grit. A quick call to our Sikkens representative was made to find out who in town was capable of making this fiberglass window look like a darkly tinted glass window. We discovered a great shop located in town; a shop that specializes in custom motorcycle design and painting. Eight weeks and $400 (CHEAP! Why couldn’t everything been this cheap during this build-up!) later, we received back from the shop a completely perfect replica of a darkly tinted back window complete with burnt orange airbrushed graphics to replicate the look of defroster lines. To this day, at the events that we have competed and showed this vehicle, no one is aware of the presence of a fiberglass back window because it is disguised so well. Most people just assume that it's a glass back window because it looks so close to the original.
Building a new back window out of fiberglass was only a small portion of the potential pitfalls associated with motorizing a window that originally came glued in place from the factory. The first issue was establishing a water channel around the window openings, to ensure that any water would be transmitted down and around the window opening instead of rushing into the window itself, and potentially damaging the amplifiers beneath. This turned out to be one of the more complex procedures in the installation of the back window assembly. A water channel was simply not located in the window frame area since the window came glued in place from the factory. We basically needed to replicate how a hatchback would have looked, if this car had come as a hatchback. Portions of the window channel were welded in place and other portions were able to be established using a special right angle type of rubber edging, similar to use in car door thresholds. Before long the entire rear window area had a functional water channel.
With the rear window being fabricated, we had to establish a hinge system from the ceiling of the car, to allow for the hinged movement of the back window from the roof area. We pored through every available woodworking magazine to find just the right hinge to use in this application. We opted on a stainless steel, 120° hinge that would be hidden during use. It is suspected that this type of hinge is most widely used in custom cabinetry, where the end-user was not interested in seeing any part of the hinge. We actually bought three or four options, and one of the options ended up- working flawlessly. To make this work, however, we needed to establish a flat and very strong mounting point for the hinges in the ceiling panel since the majority of the ceiling panel on this area is nothing more than unibody pop metal. We needed to manufacture 1/4" thick hot-rolled steel brackets, and weld them into place. Two ensure a considerable amount of installation integrity, the stainless steel hinges were also welded to the steel brackets. The hinges are now a permanent feature of the vehicle, and ensure no detectable movement in the window as it advances and retracts to and from very tight fitting water channel assembly fabricated in the rear window area.
With the hinges in place, it was now time to evaluate how the rear window would motorized up-and-down. We decided to use a pair of 6-inch Acme Select Products linear actuators. A complex, angular bracket assembly was fabricated out of aluminum flat stock, painted black, and attached to the car’s inner wheel wells, about two thirds of the way up from the bottom of the opening of the window area. The linear actuators were attached to these brackets and it seemed as if we were able to accomplish the required amount of extension using the 6 inch linear actuators, without having to resort to longer stroke actuators.
With the fiberglass window being complete, the linear actuators and stainless steel hinges installed, the entire assembly was tested on the vehicle for the first time. To show how good planning and low tolerance measurements make good sense in a super high-end installation, the back window assembly worked flawlessly the first time it was tested. The only adjustments that needed to be made were on the linear actuators themselves, to ensure that the linear actuators both open and close at the same time, and that the window rose level to the ceiling of the car. A latching, bistable relay was installed on the strut tower brace immediately beneath the passenger side linear actuator, and controls the movement of the actuators both up and down. Additionally, a mercury tilt switch was installed on the passenger side trunk lid arm, to ensure that if the trunk laid is in the up position, the rear window can not motorize and cause damage. The motorization of the rear window is controlled exclusively by the onboard computer system, and a custom, proprietary user interface (more on this will come in a moment). The cosmetic back window package was completed with small, custom-built covers to slide over the nuts and washers attached to thee hinges. You'd be surprised how much work was involved in making just those two covers! It all needed to be perfect though.
Amplifiers and Amplifier Rack Fabrication and Installation
With the back window assembly now complete, a significant level of work was given to the fabrication of a 1-inch tubular steel amplifier rack to house the four 90cm long amplifiers to be installed in the vehicle. The tubular steel was welded together, and all of the welds were massaged with the body filler, to ensure proper attention to detail in the installation. The amplifier rack was sprayed with Sikkens glossy black. The four amplifiers were then installed on to the amplifier rack using stainless steel security hardware that were drilled and tapped into the amplifier rack structure. The amplifiers were mounted and the rack was installed inside the vehicle. There are four structural points of contact on the amplifier rack; two at the bottom of the rack located directly into the shock tower supports, and two along the ceiling panel, directly into the structural support metal of the ceiling frame assembly (double-thick metal). 1/4" hex head stainless steel hardware was used to secure the amp rack in place. The amplifier heatsinks were specifically modified at the Genesis factory to include a NPT female port on each end of the heatsink, to allow for the addition of NPT fittings for the liquid cooling system. The first course of business was connecting the liquid cooling system to the four large amplifier he sinks using polyethylene tubing. Given the design of the amplifiers heat sinks, liquid physically comes in contact with the aluminum as it is channeled through the heatsink. This ensures complete and total cooling effectiveness.
Perhaps a little bit more information is required to fully understand exactly how high of a quality these amplifiers are and why we use Genesis. The amplifiers are a custom design, built specially for this project by Genesis, the manufacturer of what has become the world’s best amplifier. Genesis custom-built these amplifiers with no onboard processing, no crossovers, no subsonic filters, no input gain stage, and nothing which might be deleterious to the playback quality afforded by the amplifiers themselves. Any and all unnecessary electronics (in our most purist, in fact borderline snobby audiophile perspective) were removed from the signal path, and the amplifiers were set to unity gain, to provide their peak output at a two volt input with a signal to noise ratio which would clearly be in excess of other electronic devices in the audio system. In addition to the removal of unnecessary electronic parts, removed as a result of no processing or input stage on each amplifier, lower tolerance capacitors and resistors were used in the construction of the amplifiers as well. To complete "the package", all of the electronic manipulation done on each amplifier, both input signal and speaker output signals wiring was soldered directly to each amplifier board using silver solder. The wiring we chose to use included IXOS pure silver IX-3 interconnect cable and IXOS pure oxygen free gamma geometry cable (11-gauge copper speaker wire). The cable selection ensured that the design philosophy of creating the world's finest mobile audio system wasn't hindered in any way by a weak link, such as higher resistance or higher inductance signal and speaker wiring. Nothing was left to question---and no expenses spared. Plus the IXOS wiring offers an increased level of noise reduction and incredible industry support for super high-end vehicles such as this.
The system boasts each amplifiers in total; six Mono Block amplifiers which have been modified to increase their power output over stock form to approximately 500 watts each at four ohms (by increasing rail voltages), and two Dual Mono Xtremes that produce approximately 350 watts times two channels, per amplifier. The total system power is estimated to be approximately 4,700 watts. The Dual Mono Xtreme’s are vertically biamplified to the front midrange and tweeter, located in the custom firewall cowl area. A Legatia L3 3-inch cone midrange driver and a Legatia L1 tweeter were located in this area (more details to come on this soon). A pair of Dual Mono amplifiers are dedicated to the kick panel-mounted Legatia L8 prototype 8-inch infinite baffle subwoofers. The remaining four Dual Mono amplifiers are dedicated to a subwoofer system to be located eventually underneath the dashboard area. The original intent was to mount a very special dipole subwoofer transducer in the dashboard area (cleverly named after an ancient Greek structure). We anticipated having this driver in our hands to install in early to mid-2004, and realized after waiting approximately 20 months that we would probably never see this very special driver due to various unforeseen circumstances and other snags at the manufacturer. So as of right now, the audio system is a very simple three-way kit comprising of an 8-inch subwoofer/midwoofer, a 3-inch cone midrange, and a 19-mm dome tweeter. We have been researching the possibility of a quad coil subwoofer to be located beneath the dashboard assembly, but it is a low priority at this time as we are already achieving a considerable level of playback quality in this simple three-way front stage system currently in the vehicle. Plus, it shows the quality of the Legatia system without a thir-party subwoofer being involved. More details about the front stage system will be provided later on in this write up.
Audio Wiring Routing
With the amplifiers in place, it was time to route the speaker and RCA wires through the ceiling framework. An easy way to think about the system’s architecture is to understand that every piece of audio equipment/electronics is located in either the ceiling or in the former back window area, with just the speaker transducers being located underneath the dashboard area. Basically all of the power wiring, ground wiring, signal wiring and speaker wiring were routed neatly safely and securely throughout the ceiling utilizing, whenever possible, the factory equipped ceiling channels of this unibody car.
The power and ground wire that exited the amplifiers was routed directly to the future location of the power distribution center, located immediately behind the pair of front seats. The remainder of the wiring was channeled up through the amplifiers heat sinks and into the unibody structures of the ceiling area, and routed along the b-pillar and down the a-pillar area on each side and into the dashboard structure area, for eventual connection to the front stage speakers. The logic in wire or routing serves to fundamental purposes: first, the entire system can be easily accessed and serviced by simply removing a pair of a-pillars and the ceiling panel, and secondly, routing the wiring through the a-pillars allowed for a smooth carpeted finish on the floor with no bulges in the carpet as a result of wires being routed beneath.
More is coming soon, please be patient!
