I just pulled my drivers side (Left) rear window regulator due to the base plate being warped and the window vibrating after reaching half ways closed. The numbers stamped on the arm (connected to the gear) are 116 730 22 46 RECHTS ; and 116 730 2146 LINKS. RECHTS is German spelling of RIGHT, LINKS is German spelling for LEFT. I don't see any indication that a previous own may have swapped out the arm. Why would Mercedes create such confusion?