Polyglow is made for boats whose gellcoat is in bad shape. It's made for fiberglass with a gellcoat finish. I use it on my motorhome because it's 14 years old and the finish is in bad shape. I makes it look new again. I would not recommend it for your 3 year old unit. Once you start using it unless you keep your unit indoors you will have to treat it every year, forever. My suggesgtion to you is to worry about it less and enjoy it more.
Happy trails, Peppi
PS, It takes a lot of prep before use and from 4 to 6 coats to get a proper finish, not real hard just very time consuming.