"I'll add this one to my long list of automovtive scam designs where some 5 dollar part fails and you have to buy a complete assembly priced between $170 and $300 to fix the problem."
Have just experienced the same problem on a 190e
Rear passenger window was making an awful clunk when reaching the top/closed position.
Removed the door panel to find that the grey plastic guide jaw was unseated from the metal lifter track. Tried to push it back on but the small grooved tab [that's meant to hold it on the track] broke off!
