A common problem with Newmar motor homes. Newmar told me it was the clear coat and that they had either changed brands or the paint manufacturer had changed the instructions (cannot remember which) Either way the problem supposedly does not exist on coaches after 2009 or 2010. I tried to repair mine by lightly sanding and was going to reapply new clear coat. The color paint was so thin I could not lightly sand it without removing the color coat. I got an independent cost estimate to repaint the roof for $3000. Newmar had a special price to repaint and fix everything on the roof for $1200. I took Newmar up on their offer.
Howard,Connie,& Bella,
One spoiled schnauzer
2007 Newmar KSDP
4dr Jeep Wrangler