MB Phone cradle

[jasonyw]

I have a 2005 W211. Phone switches are on the steering wheel and audio 20.

How easy is it to wire up the MB phone cradle or it not worth the bother?

 

[Diesel Benz]

It isn't just the cradle but also a control unit and a few other parts. See an example of a kit here:
Comand Online Ltd :: Phone Retrofit Kits (MOST/D2B) :: Phone retrofit kit for MOST based cars

Many owners consider this worth while to retrofit, some consider £50 too much, only you can say if it is worth the money and the effort.