I would not expect a 6 year old fiberglass sided RV to be badly oxidized, so one of the lighter-duty polish-waxes ought to do the trick. I'd experiment with a marine/RV polish and only move to a heavier duty (coarser grit) polish or rubbing compound if necessary. A coarser grit will cut through the haze with less rubbing, though.
Besides Meguiars, there are excellent products from Turtle Wax, Star-Brite, 3M, NuFinish, and Gel Gloss Original. Dozens of boutique brands too.