Custom 3D Printed Phone Mount for Scooter

I have an electric scooter that I shipped to campus for ease of transport. Unfortunately, I was so directionally challenged that I had to pull over on every single corner to check my phone and see where I was headed. I decided to make v3 of my scooter's phone mount. 

Blue 3d printed phone holder mounted to motorized scooter handlebar
3d printed phone holder mounted to motorized scooter handle

Around a year ago, I made the first mount, which was similar to the OtterBox belt clip (if you've ever seen that). Basically, it has 2 corners that the phone slots into (like the photos above) but then on the right edge, it has a clip that locks the phone case in. Well, this design was all well and dandy until I realized that PLA was too brittle to bend such that my phone could fit in. I tried printing the design slightly larger but ended up having to put sticky-backed foam into the corners of the case. That worked surprisingly well until my friend crashed my scooter and shattered the mount. I didn't back up the file so that design was lost forever. Lesson learned. 

Enter v2. I wanted to make another mount but was in such a rush that I printed a terribly designed blocky mount that didn't even fit my phone. I actually stripped the bottom right hole on my scooter trying to attach it (which is why there are only 3 bolts - eww). Exit v2.

3d Printed phone mount before attachment to scooter
3d printed phone mount before attachment to scooter

Finally, I printed v3. The phone fits perfectly and the holes are spaced perfectly. Well actually, v3 still has some issues. After a bit of testing, the square nut (see photos above) kept rattling loose even after being epoxied in place. I ended up losing the whole knob contraption on the road somewhere.

I think my current design actually has some potential - maybe the next step is to print a clip that has a square peg that can fit in the mounting hole and lock my phone in place that way. Back to brainstorming I go!