I think I solved the mystery. My golf pull cart bag was in the back and one of the wheels was close enough to the rear door button so that when I went over a pothole, the wheel of the pull cart would nestle on the switch and pull down the window. That's also why I couldn't always get it back up until I stopped. If it happens again, though, I'll know it's something different. Mike Ecsedy, Brookfield, CT