If your car has the "Smart-Key" system, check with your dealer to see if they are substituting for the old. Smart Keys only can be programmed once by MB, PDC (factory depot) they keep the codes by VIN and they can not be reprogrammed by local dealer no matter what the seller says. There are only 24 slots available unless the computer is replaced. E bay remotes are only good for show, or if you break an identical housing on your old one.