I made the GPS mount out of .032 IAW the instructions found in the Garmin G3X installation manual. I mounted it just ahead of the stringer standoffs and under the fabric. This is one less penetration to worry about and Superflite System 7 doesn't use any silver coating that could potentially degrade the GPS signal. It's mounted above the ELT so I can run the cabling forward together with the ELT wiring.