After reading about the different choices, I opted for Mothers synthetic marine wax.
From their website:
A super-tough, one-step synthetic polymer wax, custom engineered for modern gelcoats. Our easy-to-use, high-tech formula creates a long lasting protective barrier against harmful environmental contaminants and UV rays. Removes light oxidation and leaves behind an unparalleled deep gloss shine. If it's good for boats that get plenty of exposure to sun and salt, it seems like a good choice for an RV. Waxing also helps keep black streaks away. I think application every 6 months is recommended and may depend on you location and how much time your RV spends under a cover of some sort.
I can't imagine RV manufacturers doing the highest quality gel coat applications so keeping waxed is probably a good idea.
I am also using the 303 Aerospace Protectant (applied first).
Here is some info. on
gel coat fading on boats and RVsOnly problem is finding a neighborhood kid to put the stuff on. They don't seem to do manual labor anymore.