The clamp on ones I had for my 97 F150 were great.. Didn't vibrate enough to make them unsaleable? They really worked fine for backing up into the site, and you are not going fast enough to vibrate the mirrors..
Going down the hwy, you don't need to be able to read the other vehicles license plate.. Just that they are there... Right?
Anyway, whatever works for you..
Good luck!
Mitch
2013 F150 XLT 4x4 SuperCab Max Tow Egoboost 3.73 gears #7700 GVWR #1920 payload. 2019 Rockwood Mini Lite 2511S.