Summary

Designed a little mount to attach to my rear-view mirror and fit any standard 1/4" 20 pitch (tripod) screw.
UPDATED: New knurled screw, cuts your fingers less!

Instructions

I printed this at .2mm resolution and 40% infill with 3 perimeters.
Use one M3x22mm screw and one nylock nut for the main section. One m3x10mm screw and one nylock nut for the "clamp"
If you can, print the clamp parts with a smaller infill so they will have more flex.
The screw is very strong with 40%+ infill. If you don't have a good cooling fan, should add a sister tower (or print a second screw) somewhere else on the bed to print better.
The screw should be snug enough to not fall right out.

Car-Camera mount for a cheap gopro clone