I just got this baby installed. I originally had planned on putting in a Power Acoustik double din unit but the one I received was defective. This player works great with the Ipod and Iphone. No cd player (does anyone still use these things?)
Things needed-
Alpine X305s head unit
New Metra LC-GMRC-01 GM Class 2 Data Bus Interface
Antenna adapter
Alpine X305s head unit:Alpine iDA-X305S Digital media receiver at Crutchfield.com
Metra LC-GMRC-O1 harness: Axxess LC GMRC 01 GM Class 2 Data Bus Interface | eBay
You can get everything you need for this installation at the 1st link. Crutchfield is where I got this from. Great price for a brand new head unit and it comes with everything you need except for the LC-GMRC-01 harness. (this harness doesn't retain onstar but it keeps the chimes! Be sure to put electrical tape over the chime speaker because it gets LOUD.. I have a few wraps over it and it is perfect now.)