C-Forum

Sorry, but I have a silly (but serious) question: is there any way to polish Royalex?

Only the outer layer :)

You, a Polish person, want advice on how to polish Royalex?

The outer layer is vinyl. There are vinyl cleaning and renewing products available. They should remove surface oxidation and leave the color looking dark and newer. Then you can find a "yacht" wax like those made by 3M and apply it. I have the paste wax version. It includes UV inhibitors and supposedly bonds chemically to the vinyl plastic. Don't leave your boat on a steep bank while you get your gear together. The wax may cause it to slide into the river without you.

Too slippery; makes it hard to get the roof rack straps/rope to "bite" and stay cinched up.

I use Yakima gunwale brackets, so I don't have that problem.