The driver side window in my car broke. Actually the mechanism that makes the window go up and down broke - the window is fine. I took apart the whole door and found the problem - a pastic slider that is used in the mechanism was broken. It is amaizing how complicated the mechanisms to lower and raise the window are. I found the part online, but then called up my my local BMW dealer and they had it. I drove over there and the guy just gave me the part. Back home and an hour later, things are back together and the window works. I'm very proud of this project and I think we probably saved a couple hundred dollars.