OK, well I've now tested a few paint products and techniques and think I have settled on humorously what is probably the most inexpensive and consumer oriented as likely the best
I picked up several colors of pro-quality paints from manufacturers like SEM and their finishes turned out very good. But there was a lot of prep required (strongly suggested) using their special pre-soap, adhesion promotor and finally color coat.
Since the dark "teal" color of my car is somewhat odd to match there wasn't anything off the shelf that was an exact match or even a standard color that was complimentary... I've settled with a semi-gloss black which goes well with other surfaces in the car that are black such as switchgear, vents, instruments, shifter, etc. And of course, blacked out dash panels are pretty typical, particularly starting with the 1965 Riviera.
Anyway, again, after testing a few products, I ran across a recommendation on some Jeep forums for the Rustoleum Textured Plastic Paint. This is a consumer rattle-can that doesn't require any special prep (other than reasonable cleaning of course) or adhesion promotors. It leaves a somewhat "grainy" almost light sandpaper type texture and has a low sheen.
The various reviews from the Jeep crowd were very positive both from an application and durability perspective, so I gave it a try on one of my spare door "swooshes" and the results look very good IMHO. Again, it has a nice semi-gloss (really semi-flat) finish and the texture creates a slight sheen/glow that adds a little interest. The texture looks a lot like the texture in the black plastic "accordian" slider around the shifter in fact. I think it will look very factory to anyone that isn't very familiar with the stock mono-chrome interior and dash.
The Jeep folks have been using this paint on the interior and exterior and have said it is very durable. I can attest that after applying this to my trim piece, I ran my fingernails down it, hit it with some keys and just generally abused it. Yes, especially the keys, did leave some small dents of course (more in the plastic substrate than paint) but the paint didn't chip or scratch. And with its textured finish the small blemishes are almost imperceptible. In fact, I was able to rub my fingernail scratches completely off. And according to the Jeep folks, if you do get a ding, you can just respray this stuff over and it will blend very well. This stuff is tough.
So, for anyone thinking about a black insrument panel and door "swooshes" you might want to consider this paint. It is easy to apply, very forgiving (I sprayed it in near dark at 50F which is NOT recommended, but still turned out great), looks good and is durable.... and cheap.
In my case, the only reason I'm painting the instrument panel, door "swooshes" and center console top is because my factory coatings are defective/ruined and have turned to soft goo somehow. So this is an easy fix.
I haven't painted all the parts yet, nor installed them, so I don't have any photos of how it looks complete. But I'll do so once done so folks can get an idea what the finish looks like installed and what a blacked out dash and console looks like on a dark interior colored car.
You can see what a blacked out dash looks like on a light interior colored car at the thread below. I don't think the owner used this textured paint in his application (not sure) as his looks more akin to the semi-gloss smooth finish I achieved with the SEM paint. But this can help one get an idea of the appearance.http://rivperformance.editboard.com/t5357-new-wheels-and-all-new-pics
Here is a photo of the passenge side door "swoosh" panel with the Rustoleum Textured Plastic Paint applied:
Here is a link to the Rustoleum product:http://www.rustoleum.com/product-catalog/consumer-brands/specialty/textured-paint-for-plastic-spray/
Oh, and to "strip" the old factory paint finish off the plastic parts first, soak them for about 15 minutes in the following 'Super Clean' degreaser and the old built up "padded" paint on the panels will just wipe right off. It's pretty amazing really, and you end up with cleaned parts in one whack http://www.supercleanbrands.com/products#17