If you have a PU/acrylic finish, here is a good application guide for Klasse:

http://www.autogeek.net/klasse-usa.html

From what Google tells me you have to go to W&W for "the good stuff" WX/Block. Nice franchise. I wonder what Germans use on their gel coats?

I wonder if plastidip would be a good way to protect a trailer top? https://www.dipyourcar.com/home.php