any way to do this?
i know i can just burn cds in dat format but i want my whole collection on my mp3 to work in my car

 

mp3 format will work just fine. Just burn the mp3s to a regular CD, and it will play in the stock deck. There is an FAQ for this, as well... clicky

EDIT: Wait, did you want to connect an mp3 player (iPod, etc.) to the stock deck? Because I don't think you can do that...

 

you can buy the toy-aux adapter to give you RCA inputs, or you can buy an FM Transmitter for most any type of MP3 Player.