Garmin GPS Mount iPhone Adapter

This is an adapter for my Garmin Nuvi 2555LMT windshield mount. I tried other suction windshield mounts but they didn't hold. I tried other ball mount adapters but they were too loose or snapped. I tried other Nuvi adapters but they weren't the right size. I tried other phone holders but they wouldn't hold my phone to my satisfaction. Solution? Make my own.

This mount holds an iPhone 5s (and probably other models) in a 1mm thick case and should hold securely in any orientation.

I have incl