It's always been a dream of mine to have an iPad in my car. About a year ago, I took it upon myself to make this dream a reality. What ensued was multiple weekends worth of work, bad words, cuts, and many feet of wiring.
(Self Editor Note: Since these editor's notes seem to be so popular, I will do one too. I essentially finished the main portion of this project about a year ago. Check with your state laws before embarking on something like this, and have some confidence in yourself because you WILL be chopping some stuff up. Previously, I had no experience with either car audio, nor "fabrication" or whatever this is called.)
STEP 1: Get a car.
When I reached the symbolic age of 16, instead of selling the car rotting away in our garage due to a set of bad catalytic converters and other issues, I was "gifted" it. It was a 1999 Mercedes Benz ML320. Now this car doesn't have a sterling reputation by a long shot, and it isn't exactly what one might call "exciting". None of this mattered to me however since it was mine.
Now, when I got this car it was in a rather sorry state. It used to be my dads daily driver, but he gave up on it after the exorbitant costs the dealer wanted to fix the issues it had. It sounded like a motorcycle. It had ugly headlights and faded bumpers. The battery and alternator were toasted. After fixing the "roadworthiness" issues, I set about the task of making the car interesting.
STEP 2: Make a plan.
My car came with the crappy audio setup back in 99 with 4 speakers and the stereo system acted as the amplifier. It sounded terrible. There was no subwoofer either. This project had been churning in my mind since the second generation iPad was out, and luckily for me I delayed it far enough until the iPad mini became available. Otherwise this project would have failed catastrophically. I chose an LTE iPad Mini 16GB in black. This way I could have streaming radio using AT&T's excellent LTE network in my area, and have navigation using the countless navigation apps.
During the Holiday of 2012 season I bought myself a 16GB iPad mini LTE in black, specifically for the purpose of this project. Ohhhh boy if I had known what I was getting myself into. Stupidly, since I had no idea about car audio I thought I could splice all the speakers that were there, into separate L+R channels, and just wire a 3.5mm jack to them and plug them into my iPad making act as an amplifier. This is where I was forced to learn about car audio once my cars dash was halfway disassembled. I ran out to Wal-Mart in my dads car and bought the cheapest 2 channel amp I could find, which I later blew up by overloading it.
STEP 3: Grab your tools.
The Dremel was the key tool here, along with a handy multi-meter. There were two ways to doing the wiring for this, the right way, and the lazy way. You should always do the right way. I did it the lazy (and harder) way. Since I was (as previously mentioned) completely oblivious to the world of car audio, I cut up my cars DIN harness instead of buying an adapter. Now this could have negative effects on the car in the future but I could replace the harness if I was so inclined. It was pretty simple to set the circuit for the iPad up. I chopped the harness and found switched 12V and Ground. I wired a 2amp high powered car charger to that, and then plugged in the lightning cable to that charger. The iPad would now charge whenever ignition was on, and would draw no power when it was off.
I'm sure you guys don't want to be bored with the specifics of wiring car audio, as I am sure many of you have done it, but as a beginner with zero experience it was pretty freaky. I put an amp under the drivers seat and installed an OEM subwoofer from the upgraded audio kit under the passenger seat. The amp I used was a special amp (not the walmart one), a 5 channel amp that could run in 2-channel mode to accommodate for the 3.5mm RCA cable I was using instead of using a million different RCA Y-splitters. After removing many chunks of molten plastic which had the approximate heat of the core of the earth, I finally made an indent in the plastic deep enough for the iPad to be able to be held in place with the wooden trim piece which clips over the plastic.
STEP 4: Tweak, and tweak again.
Like I said, I didn't know what I was doing. I learned everything I did in the process of doing it. The first few days of driving it a few flaws were immediately apparent. Number one, controlling the volume on the iPad was a hassle and really dangerous. Since it was the most common operation I would be doing on the iPad I then wired a volume control knob in between the iPad and the amplifier so adjusting the volume of the audio the iPad would output would be a safe thing to do while driving instead of fiddling with the screen of the iPad and taking my eyes off the road (I HIGHLY recommend you install a volume knob if you decide to do this modification.) Just leave the iPad on full volume and control it with the knob.
I then re-did the wiring since it looked like this because I didn't know what I was doing.
STEP 5: Enjoy.
I've been running this setup for a year plus. I love it. This and my projector headlight retrofit are probably the two things that made me love this car. I always get a laugh out of the unknowing people who get into my car and say "Is that an iPad?!". However the project isn't perfect. I tweak things once in a while, I added tweeters to the car which improved the sound further. I hope this inspires you to complete that project that has been sitting on the back-burner, or the project that you think you can't do. If you have any crazy project stories share them in the comments. Thanks for reading!