I will say that you're wasting your TIME and MONEY. I had a 2005 Diplomat that the clear coat started going bad on the front cap. Tried the rattle can, but issue came back. I then bought a matching color and repainted from the top of the windshield back on the front cap. That lasted about two years before it started looking bad again.
Here's the problem, you'll be chasing this issue all around the upper roof line for years. Fix this spot and another spot goes bad. You hear people say they fixed theirs with a sprayer or rattle can and it worked great, but they don't come back and tell you how it failed two years later.
There is only one repair that works. Repaint the entire roof line above the drip rail. On my Diplomat, it had three colors, brown, tan and green. All three colors rolled over the edge of the roof. Typically, the first color to go is the darker colors. When I finally realized that the clear coat issue had to be repaired professionally, I choose the lighter color in my scheme (tan) and had the entire roof line painted in the tan. We rolled the color over the dark caps and stopped the new paint at a natural break in the body. The front was the windshield and the rear was the bend in the upper cap. The total bill was $3500.00. The coach looked FANTASTIC when it was done and there was a great feeling of pride and repair when this issue was finally fixed right.
My Newmar had a paint issue at two years old along the cap on the driver's side, above the drip rail. My entire roof line was black and I knew I would eventually be repainting that roof. Newmar paid for the repair in the damaged area and I paid for the rest to be repainted.
Here is a photo where I changed the roof line on my Newmar from black to white. The white used on the roof is the white in one of body colors. It actually made the coach look longer.