We faced this same problem on our GS motorhome. There are at least 3 solutions to bring back the shine, and all require elbow grease and cash.
1. There are many automotive products made for fiberglass cars (think Corvette) that are multi-step de-ox, smooth, and shine. Price is reasonable but all require a lot of elbow grease, a poly pad polisher, and lots of time.
2. Poli Glow is a fiberglass cleaner kit made for boats, but kit gives great results on fiberglass RV finish. Restores color and provides strong UV protection. Starter kit is about 100 bucks, but easy to apply and remove.
3. The third solution was formerly called Red Max Pro, now called Zep Wet Look gym floor finish. This is the product that gives a clear shine to a basketball wood floor, used in school gyms and halls. It is cheap sold in gallon plastic jugs, and gives a great shine after about 5 coats. There are many videos free online with both for and against the product, so you decide. We have used Zep for many years and like it. But it is a clear coat, so beware that you have to use a cleaner first or you will be sealing the dirt to your finish. A pressure washer and some Bar Keepers Friend cleaning powder works for us.
Originally Posted by Tank
I have a 2005 BT Cruiser and the exterior is chalking badly from years of neglect. Any recommendations to bring back the shine and stop the chalking?