There are some very good waxes/protectorants out there, and a LOT of stuff that is just time-wasting. The best I've found so far are S100 and Meguiars. S100 goes on easy, do NOT let it dry to a haze, and wipe it off with a micro-fiber towel. Small sections at a time. I don't go over the decals, they don't need a wax. Its best to get the first coat of wax on when the RV is new. Subsequent applications are much easier.
I use that 303 stuff on leather, like my Harley seat. Excellent protection, and doesn't make the surface slippery.