I know you said, no paint. But proper prep, and adhesion promoter, followed by dye us not paint. And will hold up. I did so in the body shop with great results on tops, vinyl and plastic parts.
I have not thought about dyes. Question is will it hold up to heat?
I'm going to look more into the SEM products too. There has to be a happy medium here to reach. Never figured a simple shroud would be such an issue. Maybe I'm making too much of it. I'm just trying to make it as nice as I can and as durable of a finish. It's the picky me coming out. *sigh*