Magnetic phone stand for the dashboard, glued down by a double sided sticky tape. It can of course be used on a regular table as well.

I recommend Red 3M GoPro sticky tape, as so far it has been holding up very well for me, and even in very hot weather didn't loosen.

It should be printed with PETG, since PLA will melt when it gets hot inside of the car during summer. I printed mine in PETG, and so far it held up no problem even during hot days. 

Additional parts you will need:

• 3M GoPro sticky tape
• M4 screw
• M4 nut
• M3 screw
• Small self tapping screw and a washer, to attach the holder to the joint
• Neodymium magnet, 3cm diameter
• Some way to attach the magnet so it doesn't fall out, you can glue it in, I just used tape.

For assembly instructions, simply look at the two photos.