I've got a question on a wiring harness also. I've got a 2000 gtp. The gm harness I have plugs right into it, but there is still a small plug left that doesn't have a slot. And that plug apparently goes to the amp because when putting the factory hu back in, the speakers would not work without that plug. I've researched all over the web and couldn't find and specific gm bose harness for it.