Hi. I have put screen protectors on all my ham radios, cell phones and even my Lyman bore scope. Today I tried cutting some generic material that has always worked 100% in the past. It worked perfectly on the borescope today.
On the Garmin? Try as I may, I could not get a good bond after 3 tries. Just did not adhere to the C1's screen. I gave up. Something about the screen material.
BTW, there is a chap on eBay selling a nice sunshade for the C1. Mine was a bit too tight, but a few minutes with a Dremel resulted in a perfect fit. Cheap, too!
ron