I own a 2016 20 ft. Kodiak. We spend winters in Yuma, AZ, where our trailer sits outside for 6 mos in the famous AZ sunshine. I have noticed that the finish on the gelcoat on the side exposed to the sun has become mottled and faded looking. Does anyone have any advice or know of any products that will restore the lustre and brightness to the finish? It has become quite noticeable.