As reported in the January 2021 Aviation Consumer, I had my AA5B Grumman painted in a high-end automotive-style basecoat-clearcoat finish. Then, once the paint was cured, I had a professional aircraft detailer apply the System X Element 119 Diamond ceramic coating.
Five years later—with one or two washes along the way—the finish looks like the day it rolled out of the paint shop, except for some ugly peeling on the leading edges where surface areas were filled with body filler. The takeaway is you’ll pay a hefty premium, but in the end I think it’s well worth it.