Thread: Rain leaking into trunk on 2008 Grand Prix base

I just bought this car and I'm hoping someone has some insights into this issue. The rear window weather strip that is supposed to meet the rear of the trunk lid is leaking. On the left side (facing the rear of the car), it is almost angled 90 degrees down. I don't even know how it's possible that it could have ended up that way. There is a gap between the window and the trunk lid and you can see the channel beneath. In the middle and on the right side, the seal is more normal/flat, but it still angled down 1/4 inch or so and does not meet the trunk lid. It would leak anything running off the back window into the trunk lid channel that drains around the sides and down past the taillights? The weird thing is it's not leaking into the trunk on the left side. Rather, it's on the right side where the inside lid liner is getting soaked and then dripping into the trunk.

I tried calling the GMC dealer to get an estimate and they said if it's the seal along the bottom of the back window that is supposed to meet the trunk lid, the rear window glass has to be pulled by a "glass company" since the seal sits beneath the back window. Anyone have any experience with this? It sounds like a much bigger deal (PITA) than just replacing a simple piece of weather strip.

Thanks for any help...

Thanks for the advice. The rear windshield seal isn't leaking though. The flap that protrudes from the rear windshield seal that is supposed to cover the gap between the rear windshield and the trunk lid is warped and not sheeting the rain water properly. For the time being, I have pulled the weather strip flap up across the entire back and it is resting on the back edge of the trunk lid. Once I open the trunk of course, it will try to return to its original position. I am hoping that leaving it this way for a little while will reshape it to the way it needs to be and eliminate the leak. If not, I guess I'll have to explore replacing the entire window seal and flap (all one part)...

Did you take the trunk lid liner off to make sure it isn't the spoiler bolt holes?