if you are going to use metal cast which i recomend (its cool shit and it looks nice) your going to have to put on the metal cast ground coat it looks just like silver paint and that is pretty much the primer then the base coat color of your choice then a HIGH temp. clear coat just make sure the plenum is verry smooth and clean and it should come out nice if done right
i was also wondering for the interior of the car there are spongier areas that i want to paint like the part farther back by the e-brake on the center console and i was wondering if i painted that would it chip off or break on the spongy area????
HELL YA! That paint looks so smooth. I wish I had known of it or else I would have used it. I used some dark blue hi temp engine enamel w/o gloss. Also if you're going to paint the whole plenum mask off the ports with some tape so that way when you put the gaskets on you won't have leaks.
Topgear's got ya covered.. check out www.cardomain.com/id/topgear I put a how to on painting that sucker on there.. the only thing not listed is how to polish it so it looks like brushed aluminum or chrome but kuz has made tat available and I believe it was ryan22 that had a full detailed how 2 on polishing the plenum. Search for *tips for newbies*
The softer things that flex I would paint with a vinyl dye. Can usually be found with the rest of the rattle cans. Maybe the Krylon Fusion stuff also, but I have never tried it on soft parts only rigid plastic.
I wouldn't use paint on it, Ericksaint is right; use vinal dye.
As for the metalcast, for plastic you will have to use the groundcoat (its just a bright silver paint). If you are going to use it on a bare metal surface ie: intake plenum; you can use the metalcast alone. You do not need to use a clear topcoat, for the metalcast comes out very shiny, as you can see in the pic I posted. If you use the groundcoat with the metalcast, it ends up turning out more like a really bright blue paint and not like a candy-apple color like on my plenum. I used the groundcoat on my oil cap, P/S fluid cap, etc....
Its kinda hard to tell but the oil filler cap doesn't have quite as deep a color as the plenum.
I was going to do a how-to up on polishing the plenum and valve cover, but I do not have any good pics of the progress as I did it. If anyone is interested anyway, drop me an e-mail and I can do a write-up on it.