my right rear window on my 99 C280 would not function with no touch and would on go down if I held the switch. To get it up I had to tap on the up side of the switch. It worked however with the remote on the electronic key perfectly. I removed the center trim from the consol and noticed there is a sliding retainer type thing o jig, that cover both switches for the right side windows, and it was not slide properly in place, inteestingly enough it slides the opposite from the driver side, so I slide it to were I thought it shoudl be and that did the trick now the rear window works with once touch and hold. Note that is it opposite the other two switches for the driver side windows.