What you have is caused by a problem most RV manufacturers had with the fiberglass f from their supplier. The individual fibers raise and come to the surface. It can raise the paint off the surface. There is no permanent fix. Can repaint but will come back especially on the dark surfaces. I and many others have had the sides of our RV replaced with new and different material that is not supposed to do this
.It is called etching or checking depending on which manufacturer you talk to.
Howard,Connie,& Bella,
One spoiled schnauzer
2007 Newmar KSDP
4dr Jeep Wrangler