2WUPROMOTIONS

how do you check if your w211 is compatible?

cetialpha5

I don't even know what that means. Either you have the option or you don't. No one ever tries to add the option in later because all the component parts would probably cost over $2000 plus installation. The 4 door handles alone are about $250-$300 each plus the antennas, programming, etc.

Strigoi

Yeah, it's not something that you just add to the car.

cMazara

If you mean replacement parts, search on an epc for compatible part numbers with your vin, then go on eBay for the part.