Red Winnebago gel coat oxidation

I own a bright red Winnebago TT with gel coat finish. Despite waxing yearly and covering in the off season, it's finish has dulled considerably with splotchy oxidation. Last fall I made some headway by using my Dewalt orbital with wool pads and Meguiars 49 oxidation remover followed by Meguiars 56 Pure Wax. When I uncovered last week, I'd lost most of last year's improvement? If anyone has any advice, I will certainly appreciate it.