Since I just saw the extra key button thread again, I figured I'll share my story. When I got my 2003 C320 Wagon I got two smart keys without the trunk button. As far as I can tell that is correct. Now, my remote keyless decided not to let me open the trunk anymore when I unlocked the car and brough it to the dealer. The dealer said that I had the wrong keys and replaced them free of charge with two "trunk" button enabled keys. Am I missing something or are wagons supposed to have the keys with the trunk button?

 

No, wagons are not supposed to have the keys with the trunk button. Their keys are just like coupe keys.

 

Well, cheers to the service people for being clueless and giving me the "better" keys