<VV> Making plastic shine again

[bub049 at comcast.net]

It was a lazy Sunday afternoon, so I decided to do some detailing under the hood of the 62 Monza sedan.  I gutted it and cleaned, sanded, scraped and primed. A new coat of splatter and some clear this coming week should go nicely. Well, I brought the wiper/washer motor assembly in the house to clean and lube it, burnish the points and rebuild the bellows. I should have left things alone. Now, it all looks so nice I decided the plastic cover for the washer unit should be cleaned. Well, after degreasing and washing it, I have found that some PO sanded or scraped it to the point they dulled a lot of the shine. I know, how anal can I get; it's driver not a show car. Like I said, it was a lazy afternoon without rain, mosquitoes, or mama (the boss). 

Anyhow, does anyone have a secret to making plastic pieces shine again short of painting them with a gloss black? I used to know, many years ago, when the cars I played with were AMT/SMP plastic models, but.....it escapes me. 

Thanks in advance....
Bob Johnston
Frostbite Falls, MN