I enquired about the tow cover a while ago and have a sample of the fitting. It would stick to the dimpled finish, but I would not be happy with it.
Whilst the white fittings would visually tend to be lost on the white dimples the aluminium skin on our dimpled vans is thin and would get damaged. On the silver skinned vans the metal is stiffer and less likely to get damaged, but the fittings stand out more.
Colin