Mounting bar accessories w/o the use of brackets

I use a GPS while on roadtrips but dont want clutter on my bars in the way of brackets when its not in use. I installed a nut-cert in the bottom of my bar that I use on my modified GPS mount.
Heres a nut-cert and gun. It works like a pop-rivet gun with the use of compression to flare the nut-cert.

Heres my modified GPS mount. Its the original suction cup mount, minus suction cup, and a hole drilled for the thumb screw to attach it to the bars.

Bottom of the bars, with the nut-cert installed.