I dont have the bottoming out sound but I have heard the difference in the sound of the door shutting with the window down. It had me doing a double take.. walked back to the car and reshut the door and walked off thinking "sounds like something is just not right in there". Keep us posted if the "window fix" fixes your windows for good. mine seem to be having problems about each time I go to roll them up. Maybe this is why some beetle windows shatter mysteriously.. I got so pissed the first time it happened to me I was about to rip the damn window out. I had to just walk away..