I don't know if it's possible, but here it goes. I have a DEH-1300 from Pioneer and the question is:
Will I be able to hardwire something to the receiver so that I can hook up an MP3 player directly to it?
I'm curious because the wireless fm transmitter solution sucks a**. Sorry! In my opinion, in-dash CD players should have mini-stereo jack on front for hooking up portable MP3 players.
If it has a CD changer input you could do something like that.
There is an adaptor (CD-RB10) that would allow you to use the aux-in function on your headunit. It converts the changer input to RCA inputs, then from there you get a cable that converts RCA jacks to a headphone jack that can be plugged directly into your mp3 player.