Try polyurethane imron. It’s airplane paint. Spray it on in 3 coats, let it dry, wet sand in 600 grit, then shoot it once more.
I prefer using car paints as once you clear coat it a few times it can take a beating.
Neat trick for metal work: shoot it in iridescent pearl, wet sand it in 600 grit, then one coat in (any color)=
red= candy apple
Blue= electric
Green= hulkamania
Want to see something really cool, look up chrome illusion paint.
The color patterns shift as the car drive towards you.