I have a 2006 Envoy XL Denali. The brake light across the back, the long plastic piece blew off while driving on the highway not long after we bought it. Noone was hurt thank GOD and no damage was done to other cars. The dealer replaced it at no charge AFTER telling us that this truck is known for this happening.. No further problems till 2 months ago when once again the right side came off, luckily we noticed it while parked we removed it and put it in the back of the truck. I then noticed that the glass on the hatch was crooked, but didnt really give it too much thought. Today I was showing my husband and used the button to open the window and the right side dropped down a bit....looking underneath the HINGE was not on the glass, it was laying on top of the other part of the hinge attached to the truck. I was told to go to a collision place and see what they say, as to what needs to be fixed. Has anyone else had this issue?