ok so i have an 08 ss with the premium system. I recently acquired a double din that im going to be installing, i have already found the dash kit, my only confusion is the harness, i do have onstar and steering wheel controls but i dont care about either, nor do i care about my door chimes. what simple harness will work and retain the factory amp?

 

I haven't looked at this exact application yet, so I don't know for sure if removing the radio affects the data bus negatively like in some other GM vehicles. A simple idiot check would be to disconnect the plugs from the radio and drive around this way for a bit to determine if anything is displayed (codes or info issues).

You may be able to find an adapter in a few places. Metra Online (Edit: Metra 70-2104 is the part) and Installer.com have a number of items. You could buy the Axxess GMLAN11-100 harness kit. This is designed for the GMOS-100 adapter. Instead of using it for this, just hook up the appropriate wires as needed.

Honestly, if the HU is decent enough to replace the factory one, why not do it right and install the correct adapter and harness? You can always find one used on eBay. The GMOS-100 will even let you use XM (with the purchase of the XIA-LCD display), and it includes the SWC interface. It's not cheap, but I picked mine up for $125 from Crutchfield with my HU purchase (also on sale).