http://www.mp3-box.org/cd-mp3-player-stereo/
how do i play music from my mp3 player through my car stereo when i have a cd player installed?
you can go to radioshack or some electronic store and they will have adapters so it will work, they have them for iPods and stuff so they should have what you need
Sony Xplod Cdx-Gt710 Cd and Mp3 Player Car Stereo – CdxGt710