I bought a repair kit for a Mercedes CLK 500 rear window on ebay for $33. It includes the gear you show in the pictures, the wire and some guides. I wouldn't be surprised that it would work on a Crossfire. Try using the SLK 320 (R170) and see if it is not in the cross reference as to cars the part is compatible with.
PS The part was shipped from Sun City West, AZ name on the receipt was Gail L. Horst. Maybe that is near you ?