It is not.
You need the iPod kit for A, B, C, CLK, ML, GL, R class
There was a part with UK RRP £207 inc VAT which has just been superceeded with one that costs just under £250. The difference is the new one charges the newer iPods whereas the last one does not. (different connecting lead between the control unit and iPod, but you can buy that lead for under £25 on its own!)
New part is B6 782 455 old one was B6 782 4254
Richard
Comand Online Ltd :: iPod Kits :: Mercedes iPod kit for A, B, W203-C, CLK, ML, GL, R, Vito, Viano with COMAND or Audio-20-CD