Did I paint this exterior molding right?

The rear quarter panel moldings are peeling its factory clear coat on my 2016 Prius. I've repainted one so far- not quite done.
It was black, and I'm painting it black.

I washed it, sanded it well with 400 grit. Then, I rubbed it down with alcohol and made sure it evaporated. After that, I used Dupli-color Plastic Adhesion Promoter (for enamel paint on plastic automotive parts interior and exterior). Following can instructions, I applied 3 light coats, 3 minutes apart. Then, within 10 minutes of last adhesion promoter coat, as can said, I applied 3 light coats of Rustoleum Acrylic Enamel -Automotive Grade- Gloss Black (can specifically states it bonds to plastic).
The entire thing is not a uniform shine, so in 48 hours (can says within 1 hour OR after 48 hours), I was going to add second application of the gloss black. An hour after that, I was going to apply 2-3 coats of Rustoleum Crystal Clear Enamel and then consider it done.

My questions are, am I missing anything in there? I saw a video where guy says to add sealer/primer after adhesion-promoter coat but prior to black coat?

Do I need to add anything, or need to sand, between the two black applications? (I planned on a light sand before the second black application, as a couple fuzzies got in there).

Also, is Rustoleum Crystal Clear Enamel a good clear coat? Is there a better one or one geared toward auto plastic?

Thank you in advance.