Car is a 1996 Bonneville, tan interior. Driver'* door sill plastic panel takes obvious abuse, and I'd like to paint it. Replacement doesn't seem to be a realistic option, as that piece goes all the way back and includes the seat belt reel cover. I'd never find a good used or new one, so paint it is.

I've had good luck with Duplicolor sprays- anyone have a better idea or source?

Get whatever works for plastic. Rustoleum is a good brand too.

Looking into SEM interior paint, my experience tells me they're stuff is superior. Only issue is matching it up with my tan interior color, will have to go to auto body supply place to verify. I believe the '96 Bonneville is "saddle tan", but you never know until you see a sample. Here'* a link to the SEM spray:

http://www.summitracing.com/parts/smm-15033/overview/

Take the trim piece in. They can color scan it and duplicate it that way.

I can't help on the paint selection, but can provide a piece of advice from someone who works for an interior trim supplier. Interior trim pieces below the beltline are usually made from polypropylene which develops a film of paraffin on the surface. When we paint PP parts we etch them with a chemical solution, or flame them to burn off the paraffin. Before you paint the part use a propane torch and lightly dust the surface with the flame. Not enough to damage the plastic, but you want to burn that layer of paraffin off. Paint does not stick to paraffin.

Interesting! I've never heard that before, and thought I'd be good with a wipe down with acetone.

For the interior pieces, I like using SEM paint. It adheres really well on plastic pieces.