After much research and consideration I decided the proper replacement for my dying iPod was to install an Apple Mac mini in my Corvette. I relied on a number of resources to gather information and help make decisions on what to buy and how to overcome all of the little challenges associated with such a custom system. In a series of blog posts I’ll be sharing my approach and progress on the project. When complete I’ll consolidate the posts into a single resource in hopes of spreading the knowledge I found elsewhere and also hoping to provide a few new ideas.

Project Table of Contents
1) Pre-Installation planning
2) Electrical Installation
3) Final mounts & demo video

First, the why.
The common music player for cars these days is of course the one and only iPod. Besides the untimely death of my upgraded 1st gen iPod which held on like a champ for nearly 6 years before giving up the ghost, there were several advantages in upgrading to a full computer. My primary objectives were:

• Unlimited music storage - can install a bigger hard drive at any time
• Better/safer usability while driving - large touchscreen display vs iPod display
• GPS - why spend $400 dollars for one GPS system when a computer can run any of 20 different software versions?
• Handsfree cell phone with play-through the audio system
• Automatic Wifi synchronization of my primary music library to the car
• Plain ol’ geek factor

Decisions, decisions.
I started my research primarily with the help of two sites: MP3car.com and MacVroom.com. I quickly learned that there were several options for components and a wide range of opinions as to which were the best. While I’ll be adding more of the above functionality in time, here are the current components I’ve decided upon and why:

Computer
Apple Mac mini 1.66GHz Intel Core Duo/512MB RAM/60GB HD/Combo Drive/802.11g Wifi/Bluetooth 2.0. After briefly considering a laptop it became quickly evident that the Mac mini was the only way to go. It’s small size makes it perfect to tuck somewhere hidden in a car and several people have already used Mac mini’s in car installations so I figured their experiences would be helpful. The final factor that made it a no-brainer was when I found a company that was already manufacturing a power cable that allowed plug and play hook up from a DC power source to the Mac mini, more on that later. Cost: ~$450

Display
Xenarc 700TS 7″ touchscreen LCD display - Besides being designed specifically for automotive applications, the Xenarc 700TS is widely regarded as a higher quality, more durable display than it’s leading competitor, the Lilliput 619GL-70NP. The Xenarc was $100 more than the Lilliput so the debate between the brands was a heavy one. Both displays offer 800×480 native resolutions via VGA input, but I found far to many complaints of premature failure with Lilliput models. The Xenarc also offers auto power on when it receives a video signal, a 5-wire resistive touchscreen panel (more accurate and durable than the common 4-wire), and more actively developed video drives for Mac OS X (along those lines the Lilliput website is very poor - something that speaks volumes about a company’s quality). Brightness was a major concern I had because even though I have dark tinted windows, I also have a targa removable roof and I feared direct sunlight would make either screen unreadable. Depending on which specs you read (annoying that they all seemed to differ a bit) the Xenarc was ever so slightly dimmer at 330 cd/m² vs 350 cd/m², however Xenarc offers a reflective backlight insert that can be installed to increase brightness another 100 cd/m² - something I’ve not heard anyone’s experience with, but it’s nice to know the option exists. Finally, both offer USB touchscreen output making for easy connection to the Mac mini. This project was going to end up being a lot of work and a fair monetary investment, I didn’t want to take a chance that the weak link in the system would be the display - the only thing I’d interact with on a daily basis. Cost: ~$360

Power
Choosing how to power the system was far simpler. Thanks to a fantastic company called CarNetix, they’ve really taken the guess work out of the power source. I ordered up the CarNetix CNX-P1900 DC-DC power regulator. They also recently introduced a pre-made Mac mini power cable that allows plug and play connections to the P1900 for both DC power and a simulated power on/off button press. I can’t say enough good things about this company. The product is high quality, well thought out - allowing for a dozen different operating configurations, relatively inexpensive for what it does, and the support staff (who I’m guessing are also the engineers) are responsive and all around great. Everyone should put a computer in their car to keep this company alive. Cost: ~$100

Audio
The audio connection was effortless at this point since I had installed a Sony head unit with an auxiliary input box years ago. While getting rid of the awful AC Delco GM standard issue head unit is a must if you want quality audio in a Corvette, the job was not an easy one. Like all things Bose the stock audio system was extremely proprietary and difficult to modify at every step. The specific details have long since faded from my brain but for those interested in what little information I recorded at the time, I’ll link to what I can:

• Headunit: Sony CDX-C790
• Audio Input: Sony AUX-300 which provides several RCA and USB audio inputs. I had been using this box to input audio from my iPod via an RCA to 3/8″ stereo cable. That cable remains for connecting a passengers iPod, and I simply added another RCA to 3/8″ cable plugging into the audio out of the Mac mini.
• Front speakers: Bose mid-woofers and integrated twiddler (twiddler, really? what product manager at Bose decided on that?)
• Rear Speakers: Eclipse EX 6 1/4″ two way rounds
• Sub woofer: 12″ dual voice coil Blaupunkt with custom MDF sealed enclosure (if anyone is interested on the exact enclosure specs, I’ve been meaning to dig them up and post them, so feel free to ask)
• Amplifier: Kicker Impulse 35×4 bridged, 1.0 farad capacitor (save your alternator!).

Software
Since my primary OS will be Mac OS X, I spent some time trying different integrated front ends that would combine access to music, GPS, telephone, etc, but unfortunately found very few options. The most promising was an application called AMP and was undergoing an overhaul when the developer abandoned the project. However the original version is still available for download and is being actively used in several CarMac projects. I personally haven’t given AMP a full shake down since I’ve been focusing on the hardware installation. And since I don’t yet have GPS or cell phone software running, I’ve simply been running iTunes in one of three modes. My primary hardware install has been complete for about 3 weeks, here are few notes on using those options for audio access:

• Full screen Cover Flow is a recently added feature to iTunes and is perfect for an in-car display. I usually just listen on random and if you get a song you don’t like, you have forward and backwards buttons available. They are a little smaller than I’d like at 800×480, but still manageable. It displays the album art and has a sweet animation when it changes to another song. I’m using this about 80% of the time.

• iTunes visualizer looks incredible, especially at night. I had some concerns that the display would be too bright and distracting at night and I’d have to juggle some kind of dimmer settings, but this turns out to not be the case. The only time the display becomes slightly overwhelming at night is when the visualizer cycles past an almost totally white screen. The downside to the visualizer is that it’s hard to activate, you have hit the iTunes “View” menu and select it, and you have no controls to quickly change songs while it’s running. The visualizer works great for listening to long playlists you know you like.

• Front Row is the only real option for searching and selecting a particular song. The iTunes menus themselves are far to small to use while driving. Front Row however, poses a few challenges. One is that it offers no support for USB input. This means it wont work by touching the display. My first thought for a workaround was to remove the IR receiver from the Mac mini and extend it to someplace on the dash so that it could be accessed with the standard Front Row remote control. Before I got to this I found a great little app that offers an iPod-like button overly and allows you to use touchscreen controls to navigate the Front Row menus. It’s called Front Row Remote and works well to solve the problem. The only real draw back is that scrolling through thousands of songs or albums takes your eyes off the road and sometimes takes a while to locate the track you wanted. This isn’t a flaw in Front Row Remote, simply a result of having a lot of music that probably wont be totally resolved until we have solid voice activation and you can just speak the artist and title of a song and have it play.

Installation Planning
Display placement
Every car is a bit different, so the biggest challenge here is usually where and how to mount the LCD display. In the case of a fifth generation Corvette, there is a cigarette lighter and ash tray at the bottom of the center console stack, just begging to be removed for a better cause. That in combination with the removal of the original stereo head unit which was a double DIN, (which meant my single DIN Sony head unit required a large bezel to fill up the extra space all these years) now means there is just enough space for the 4″ of vertical space a 7″ display requires.

Computer Placement
The second most challenging thing to plan is where to put the computer. In this case I had about a 7″x7″x4″ box to stuff somewhere. There’s not much cabin space inside a Corvette, so I only had 3 options to consider: behind the drivers seat, in the glove box, or in the trunk. I finally decided upon the glove box because it would allow quick access to the Mac mini to insert DVDs/CDs and remove it from the car. However, this was the least ventilated option and the fears I had of overheating are turning out to be correct - the unit has almost no fresh air and after sitting in a sealed car in the hot California sun, it’s starting to cook. I can hear the Mac mini’s fans spin up to full speed in an effort to keep breathing and not force a shut down, and so far it’s been usable. But for the long term I’m going to have either provide extra ventilation to the glove box or relocate the Mac mini. The trunk would make for a decent location, except that all cables would have to be extended, which is 1) a pain and 2) VGA video signals deteriorate the longer they are and splicing into the nice VGA cable that came with the Xenarc display would be a real shame. I’ll have to see how things go as the summer heats up, but long term heat only shortens the overall life of a computer. Moral: plan for proper ventilation.

Power
Since the Carnetix P1900 power supply is only about 5″x3″x2″ it can be easily installed up under the dash behind the glove box, above the passenger foot well. Another consideration in the power department is how you want to turn the computer on and off. The P1900 allows for a simulated power on button press sent to the Mac mini when you turn the ignition of the car. It then allows for a “sleep” command to be sent when you turn off the ignition. I have mixed feelings about leaving the Mac mini asleep for any long period of time, draining the car battery. It uses less than 2 watts while asleep and the P1900 has a dead man timer that will kill power to the computer if it senses the voltage of the car battery drop below a certain level. But all that wasn’t enough certainty for me to go the sleep route, and instead I’ve been using power on and power off with every ignition. Boot time is quick, the system is ready to go usually before I’ve backed out of a parking space, and shut down is made faster with the a single tap to this AppleScript which I keep in the dock. Just make sure you turn the ignition off first, then tap the shutdown script, otherwise the P1900 will send another “power on/off” signal to the Mac mini after the shutdown sequence has begun, which usually results in it booting back up as soon as it shuts off. I also installed a 30AMP inline fuse between the car battery and the P1900. This is an extra safety precaution to help prevent any power surges from damaging the P1900.

Valet switch
Also power related is the option to prevent the P1900 from receiving the “power on” signal when you turn the car’s ignition. This option was suggested in the P1900 manual and I HIGHLY recommend everyone do it. I installed this rocker switch hidden up under the driver’s side of the dash. By switching to the “off” position, it blocks the P1900 from receiving the “power on” signal when you start the car. This is a must for when your car is in for service and you don’t want someone fiddling with your computer. It’s also handy for those really short trips where booting the system isn’t worth it. I found that even if you turn on the car with the valet switch in the “off” position, you can still turn it “on” and then press the Mac mini power button and the system will boot if later decide you want the computer on.

Dash fit and finish
Completing a custom install like this and making it look stock is always challenging. My goal was to mount the LCD display flush in the dash and have it appear as though it had always been there. This is easier said than done I have yet to work out the details on creating a custom bezel for the display. Everything is mounted temporarily for now and I’ll post more information as I move through the bezel creation process.

Tools
• DC voltmeter, don’t bother starting the installation without one. Horror stories of people frying brand new LCD displays, computers, or worse, are all to common. They’re only $20 or less at Radio Shack and it’s always handy to have around. Use it to check for polarity when splicing wires, check for resistance while choosing good grounds, and check for voltage values to ensure you’re not overloading your components. Remember to check, double check, and re-check before applying power to something expensive and/or soldiering wires permanently.
• A full socket wrench set is a must for any automotive work. Also standard screw drivers and wire strippers.
• Soldering iron, solder and a helping hand if you’re going it alone.
• And lastly some Miscellaneous items such as electrical tape, zip ties, heat shrink tubing for finishing solder joints, ring terminals for connecting to the car’s battery post and ground points. Lots of 12 gauge wire in at least two different colors to separate positive from negative.

Time
Plan a few full days from to start to finish. My install took around 14 hours over two days.

Continue to part 2: Installation >>

Project Table of Contents
1) Pre-Installation planning
2) Electrical Installation
3) Final mounts & demo video