I have the factory radio in the '05. Has amplified speakers front, middle and rear with pillar tweeters and factory sub in the back. 6-disc changer in dash with aux in connected to the factory ceiling DVD player, XM built-in, steering wheel controls and back seat controls for a 2nd program (head unit plays 2 sources at once). I don't want to mess with it because it sounds good and does a lot. I would love mp3 player remote controls, but don't know if that's possible. Technically I can run a line in from the DVD player by setting the dash unit to "RSE", but having the plugs on the ceiling isn't ideal (plus then the kids can't watch a movie). I don't know if anybody makes a real line-in adapter since it's already connected to so many sources.