I bought some paint in spray cans that match the original car color
well. I also bought adhesion promoter, primer (metal and
rubber-plastic) and clear coat to use too.

I'm concerned after spraying a test area (I'm an amateur) that I can't
get the area I paint properly buffed / shined. I know the paint's web
site gives instructions but I think my efforts won't get it right. Is
there a trick to get the paint w/ clear coat I apply, buffed / shined
so that it looks like the original ?

Also do I need the adhesion promoter on metal where I'll touch up or
just start with the metal primer? I know it's needed on the
rubber/plastic bumpers.