loulong is absolutely correct, your motorhome came from the factory with no clearcoat applied. This is a cheap fix notorious in the market of auto's as well to make a sale. Normally no sanding is ever done for adhesion, it is wiped down with a pre-cleaner and then sprayed. My knowledge comes form 30+ years in the AutoBody Buisness, and I've seen all the tricks.
My Southwind as well did not come with any clearcoat, fortunately mine is in great shape, even the factory stripping.
My suggestion, spend a week-end with a small pressure washer and have @ it. Once started it will fly off with pressure. Then get some good Polish/Cleaner and spend another week-end waxing, Wax ON-Wax Off. Good Luck,