I tried their trim spray paint and absolutely hated it. I even used their special trim primer before I sprayed the black trim paint.
FWIW, re: etching primer - although I HATE napa - the etching primer they sell for $6-ish a can is darn good stuff. Not sure who makes it.
Seymour makes a pretty good line of primer & industrial paints ala' rattle can, I've heard.....
If you are trying to match a finish color on a body, some pro paint shops can match the color of your car with a handheld scanner doo-hickey, mix some paint and put it in a rattle can for you.