IIRC, there was a thread about the rear hatch panel (where the sub is on the M&T) coming apart from the body clips. Can't seem to find it and I'm going in for warranty work tomorrow. Does anybody remember this thread?
kunkstyle, I posted recently that I got a hairline crack on the plastic interior of my hatch. When the service manager attempted to pull it off with his "special tool" he broke off two of the plastic anchors attached to the hatch, resulting in him ordering a new one for my '09. I hope you find what you are looking for. Bottom line from my experience, you won't be able to take the upper panel off without breaking something.
Looks like I'm taking the Pontiac to a Chev dealer more often. No haggling to get the rear panel replaced and they fixed my P0012. Way better service than where I bought the car.