I really like the MagSafe mounting idea from Apple and bought the Car Vent Mount PRO with MagSafe from Belkin when it came out. But after a while the fact that it hangs on my vent kind of bugged me.
Also, in my car (a VW), I have a universal phone holder cradle. A while back I purchased a module / adapter for it (Bury system 9 is the generic name for the system, I believe).
So I made a new backplate which can replace the one with the actual vent mount from Belkin and mounted it in the car.
I have separated the “four hook adapter" part from the “Belkin adapter” part so they can both print without supports with the open side up.
I printed it in Prusament Galaxy Black PLA (0.2mm Quality profile) and superglued the two parts together.
It survived already one summer in the car.
Again, after a while I introduced a ball joint into the game since I wanted the phone to be closer and more tilted towards me. Since the ball joint did not have the four hooks on both ends I screwed it into the (feature-less) faceplate of the holder.
From the side it looks quite funny, but the end-user (me) is happy.
Links:
The car adapter (comes with USB for Powersupply)
Belkin's Car Vent Mount PRO with MagSafe
The author hasn't provided the model origin yet.