I'm tring to find a simple wiring adapter for a 2008 with onstar and xm. But I really don't care if I loose the onstar, xm and chimes.I was hoping to find something around $10 just so I don't have to alter the factory harness. I'm going to run my speakers off an amp so all I need is to get power, ign and ground out of the harness(I think???) Does anyone know the colors of these wires if I end up wiring it in. i'm guessing red, yellow and black but I havn't looked. Is there anything I have to worry about bypassing?