I recently rolled my driver side window down, and that is where it stayed, down. I checked the fuse in the floor board panel, #29, it checked out good. I then took the door panel off. Found a very helpful diagram on the forum of how the take the screws and snaps off in sequence. Once inside the door I seen what made the screeching sound on my window as it went down. There is a small piece of white plastic in the upper left hand side of the door panel that is broken. I looked on the GM parts site for the part, all I can find is the whole assembly, part number 20897018. Has any one had this problem before and how did you fix it? Will I have to replace the whole power window regulator, or is there a way to just replace this small white plastic piece. The motor still works fine. I was able to get the window up some, but not enough to keep from having to cover my car.