Remarks:
a) I'm not a craftsman
b) The part (ProClip) must be built not necessarily on the left side, because you can push it to the right side
c) By the later attached Navi (5 inches) will obscure the visual parking aid of the B-class
d) The Navi "shakes" is no longer driving.
The ball joint I have to absolutely simple "assembly" of the ProClip behind provided with double-sided tape and stuck to the plate of the ProClip, in such a way that the 4 holes fit in the ball joint to the 4 holes of the ProClip and then selbige with the 4 screws firmly bolted together. ZACK - DONE! That's it, really. Not 5 minutes of effort - and no technical skills required.
The staple is then pressed onto the ball joint, which is provided for holding the Garmin navigation systems.
That's all - over and out!
I would recommend buying these parts highly enough.
All in all a super-sub, whose short-term higher price pays to view all.