Rattle can help
1) Clean the area real good
2) Take care of the scratch if there is any depth with a little fiberglass bondo. Smooth that down smooth (150 grit, work up to 600 grit)
3) Clean the area again
4) Tape off the entire molding piece on the door(you need to paint the entire piece).
5) Get a Scotch red scratch pad and
6) Wipe the area down with a paint prep cleaner solution (it will get rid of oil, fingerprints, dust, etcetera)
7) 1 light coat of self etching primer (will etch plastic). . . .don't waste you money on adhesion promoter crap.
8) Sand with ~1000 grit wet
9) Check for any imperfections, repeat any previous steps if neccesary
10) Clean with prep cleaner again
11) Let dry fully
12) Time for paint. . .1 light coat at a time, 3 coats should do it, but make sure you have good coverage. If it is metallic make sure to follow one direction down the piece otherwise it will look el crapo. Let it dry for a couple hours.
13) Wet sand with 1200 or up grit, just lightly to get orange peel out
14) Clean with water
15) A couple coats of clear
16) Buff with a fine finishing compound
Hope that helps,
Ed

