You are not going to like my answer. That vintage coach (along with other brands) has this problem. It may go deeper than the clear coat. It may go right to the fiberglass wall. The situation will get worse, over time. The only remedy is to have the walls of the coach replaced. Newmar has had a program to help owners with the cost. Contact Newmar for details. The problem is with the material used to make the walls.
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
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