I believe my AUX adapter is made by USA Spec. it states works only up to 05 Grand Prixs but this is patently false. it works fine in my 08 GXP Single CD w/Monsoon.
Yes...it typically helps to have XM capability. If your car is XM ready or has XM already installed you can install the USA Spec adapter in one of TWO ways.
1. XM piggyback. this connects inline with your XM box in the trunk or connects to the XM harness there if it exists. This allows Text on the HUD, steering wheel controls, and a couple other things.
2. CD Changer method. this involves installing it to the cd changer port on the back of the head unit.
It will work for both iPods and offers an RCA input as well.
USA Spec iPod® Interface for GM Connects your iPod to select 2000-up GM factory radios at Crutchfield.com
Pain free. Only downside is the harnesses are BARELY long enough for the box that if you use the XM install method and stretch everything out you can get the adapter to the middle back of the trunk along the seat and this is ABSOLUTELY REQUIRED to get enough ipod cable up into your center console.
