Clear coat of flat stripe

I would say the reason he won't do it is that the clear is likely to crack after awhile.
I have a couple of Shelby Dakotas and the hood stripe won't last over a couple of years on those due to the engine heat. After replacing the first one and needing another after a couple of years I got the bright idea to clear over it to preserve it. I sanded the whole hood with 600, put a new decal on, shot a couple of coats of clear, sanded it again to get rid of the edge, and shot a couple more coats of clear. It was BEAUTIFUL ! It looked great until I noticed something funny when the weather turned cold. Turns out the clear was cracking on the decal and it eventually came off in big sheets. Great idea but didn't turn out as planned.
Dallas
That sucked.
That would definitely be a good reason not to clear over them. lol