This is a floating window that is not bonded to the body like a windshield. A bolt below the glass holds it in place, and if the bolt is lose or snaps off (like mine did) it will "slap" against the window frame on certain bumps. This section of the body takes high torsional and bending loads and there is a bit of flex here. If the window is not tight, it will make noise as the body is torqued. Insulation or a new bolt will do the trick.

However, the dealers are not experienced with this repair, so make sure they understand the problem. The bolt is accessed by removing the cap where the shoulder belt feeds into the door jamb.

You are better off finding a dealer who has made this repair before. Otherwise the car will be out of commission for a while. Mine was gone for 4 days. Grrrr.

Good luck