Hi, I just got my iPhone 5s bluetooth connection working in my 2009 CLK550, so hopefully it works the same on you W209 CLK55. First check the "phone jack" in your center console, if it is a small piece (2 finger length) then it is just a base connector and you need to buy the MB bluetooth cradle. I bought mine from amazon from reggy275 for $195 used (MB dealer quoted $500, other amazon sellers are at least $100 more than reggy275). It came 2 days ago and I snap it onto the base connector, start the car, press the MB symbol on the cradle (start the bluetooth scanning) and check your iPhone bluetooth system (if you pair any phone to a car's bluetooth, you know what I mean), you'll see "MB phone system" come up and you need the pairing code (5-digit number, it's inside the cradle butt, you'll need to slide its butt cover off to see that code). It pairs immediately with my iPhone 5s and my son's iPhone 6, we both can make calls from the keypad on the dash and receive calls on car's audio system. Hope that helps.