The rear windows of my 95 S420 don't respond properly to the switches after a couple of years (maybe longer) of inactivity. Lowering is not a problem but the movement is slow. I can raise the windows if I help the glass up. At the end of the travel there is a moment of what sounds like a gear slipping before the the motor stops. With the left rear window partially down, there is about 3 cm of vertical play in the glass. The right rear window is much more tightly in place.

Can someone help me with what the 'cheap' redesigned parts are called and possibly the part numbers?

Thanks,
Sixto
95 S420 ... $80K car full of brittle plastic gears!
87 300SDL ... $60K car with one brittle aluminum part