the tape i used this time is about 2mm thick and is a soft foam so it should deform around the dots nicely. the gray stuff came off the mount surprisingly easy. didnt have to scrape or anything and left no residue, so it probably was the problem. not blaming anyone, just probably a bad batch of adhesive. i already had some tape in my toolbox so it didnt cost me anything to fix it.
i used adhesive promoter on the mount before putting on the new tape, then put some on the windshield too, after scraping it with a razor and scrubbing with windex/ammonia. gonna leave it to cure overnight before i put the camera back in since my wife will be out driving in the morning and it seems like her car is a magnet for crazy drivers. thus the dash cam.
i didn't have to go thru this much trouble when mounting the f70 in my 1998 camry, but then it doesn't have those painted dots on the windshield either.