Alpine makes something like this to control an iPod for their setups. Another company makes adapters to get the AUX into a CD changer bus, as well, but there's no control.Originally Posted by tch
You're pretty much on your own here.
Realistically, if you figure out which pins are sending data and could cobble together a serial cable, you could read the data on the PC. From there, it's a matter of what signal does what, and translating that to an MP3 player, be it carPC or an iPod or something else.
This is assuming the cd changer buss in your head unit is a serial signal. It probably is.
Not a guarantee, but you can always try.