The Alpine units requires an adapter. I'm currently using the Alpine CHAS634 (mp3 capable) with a Soundgate ABMW35 adapter (been using it for almost 6 years now without issues) - I'll post a picture of my setup when I get home tonight if you want to see it. If you can find a used OEM (post 2005 models also have MP3 capability), that would be the least hassle. You might also need to get the CD changer bracket kit somewhere as well.