Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4857222.
There are a number of different types of devices for automotive use (phone mounts, GPS, backup cams, etc) that connect to a stand using a socket that fits over a 17mm ball. This is a replacement stand for those devices. I made it to replace one that had a suction cup on it in order to mount to a window. This one simply has a flat bottom so it can be attached somewhere with double sided foam tape.
I have included two versions. There is a single piece design that can just be printed and used, because I know some people prefer that, but I also wanted to make a two piece design because I'm a big believer in optimizing strength by orienting layer lines properly, and the two piece design allows you to print the base and the "arm" in different orientations to make them both as strong as possible. You will need to find an appropriate screw to attach the two pieces together. I just found a screw in my "spare screw bucket", so I'm not sure exactly what it is, but I recommend something with coarse threads. Screw length should be no more than about 12mm long (and not too short), and minor diameter should be about 3mm.