It's a base for your desired mount so feel free to add anything that can hold your smartphone in an appropriated way.
e.g.: I taped a strong magnet to the clamp and inserted a metal plate between my smartphone and the cover. Even on rough streets the clamp and my smartphone doesn't move a bit.
Originally designed for the Golf 7 with a thight fit.
The Air-Vent behind the clamp can still be moved.
First you align the top piece (not the round side) and "clip" it to the top of the vent.
Then you just have to bend the clamp until it can be inserted on the bottom of the vent.