ADK and IP bus/CAN bus: Control android media player through pioneer head unit?

HI all, Arduino noob here!
I just got an old pioneer car stereo for free, and I would like to listen to my android media an control the player via the head unit for security reasons, using the ip bus connector (the one used by cd changers).
I found a pioneer cd changer emulator that uses an ATMega8 to interface an usb mp3 player (yammp3). I have attached the schematics and the source code since I cannot acces the website today.
I just discovered that android ADK has audio over usb capabilities, so it's just a matter of translating the code of the emulator and adapting it to my needs (time to remember my programming skills!).
I also realized that arduino due is ADK ready and has a CAN bus interface, and that there's a library available so I think is the ideal for this project!
according to this, I only need a CAN transceiver (with built in comparator) and few other components to get the phisical layer done
Add a Car voltage regulator and I'm done with the soldering iron!

Am I correct or am I missing something? Any other advice?
Thanks for the attention (23 KB)

some thoughts about the in-car power supply:
Since I don't need arduino be on all the time, but only when the HU is on and set to the cd changer source, I don't need the circuit I linked before. I searched for a ready made dc-dc converter, and I came up with an LM2596S board (I'd buy arduino due and some other components from the same ebay seller). Unfortunately the ON/OFF pin seems to be always set to on (at least from what the seller told me).
From the multi cd emulator posted above, I know that on the ip-bus there's an ASENBUS pin that emits a 12V 20mA signal.
What's the best way to turn on/off arduino? use that signal to put arduino in sleep mode or simply use a relay (driven by a transistor) to cut the power before the DC converter?

Just curious, how your project progress?

unfortunately I abandoned the project, too time/money consuming for listen to music a few miles a week :wink:
I find out how to enable aux-in from the ip-bus, so I'm using a home made adapter to attach my android via 3.5mm jack.
A smartphone mount and the right application (for now is Car Tunes) an I can control my "jukebox" easily via gestures.