I have a 2008 Pontiac grand Prix in which I recently installed an aftermarket radio in. Can anyone point me in the right direction of the correct wiring harness? I've seen multiple options on the internet and not sure which one is correct. No 0nstar, no premium sound. I have the correct steering wheel control harness but the incorrect interface. The dash and lights turn on and off randomly since the install and I've been told it's due to the incorrect interface. Can anyone help me get on the right path?