I herd that when you replace the stock stereo that it is difficult to instal because of the onstar. My question is how do i instal it then? I have a 7 in touchscreen stereo that I would like to instal here soon but have no way of knowing how to go about it any ideas? Thanks

 

you just need a harness. I believe it is the Gmos-01, and it is around the $120 mark.