I wasn't happy with the options for mounting my Mobius Action Cam to my car windscreen for DVR use. Most were too bulky, or hung down too far, and i was after a mount which made it more discrete. I decided to disassemble one of the screen mounts I had and design an adaptor to do the job. I've included a few different angles, but have only tested 10 degrees which I found to be perfect in my Audi A3. I would assume it would be a good angle for most similar size cars.

I've included the OpenSCAD file if you wish to make modifications.

I would recommend using ABS or other filament which is resistant to heat. My initial print was in PLA, and the heat in the car was enough to warp the plastic and allow to camera to move about. The replacement ABS part remained in shape.