It works!!! For those of us who have been frustrated with the new interface cables that dont charge our newer iPods and Iphones I have found the cable that works. Part Number A-0018278404. The weird "not designed for iPhone" message will still appear but it charges and with the iPods there is no problem and no message. Cost me $ 67 dollars at Tampa Mercedes... It only has a an ipod insert , unlike the non-charging media interface cable that had a 3.5mm aux jack. Pictures posted. Jesse on Benz blogger will have a full review in the next few days.
http://www.benzblogger.com/
PS: She just won the Mercedes of North America walk around in colorado, so she knows her stuff. Ohh, if you need a car she can get it for you and she will know all the gadgetry, unlike some of the sales people in the area.