Already replaced the switches and have had no problems since then on 1998 ML320, but yesterday the rear window was accidentally sent by my elbow and I heard a loud pop and something broke hitting bottom of door! Further investigation reveals that a rather large plastic ring that seems to guide the cable has broken and the cable is just hanging loose in the door! Can't figure out if I just need to find another White Plastic Ring cable guide(don't really know what to call it) or how I am going to fix this problem? For now disconnected the power to motor and wedged the window up so it wont fall down inside the door! Anyone have a similar problem with the rear power windows? Any advice or is this something I will have to visit the dealer to get fixed? Searched for the actual piece that broke but can't seem to find it. PLEASE HELP with any advice, Thanks!