Per the owner's manual, since I never really paid attention to the unit installed in the '07 H3 we had in the center.
Two slots, one for CDs, one for DVDs.
GM will not allow you to play movies from a screen viewable from the driver's seat...liability is too high, and many lawyers are going after people on this. Many states are considering laws to make this illegal.
As for aux inputs and outputs, there are no photos of the rear of the unit, and the schematics do not show any detail.
As for the unit I glanced at, it was installed so I did not see the back.
Pictures...illustrations? On my hard drive
