I did my aircleaner lid with rustoleum flat black, then put the lid on the floor, and held a can of silver paint about 4 feet in the air and lightly misted it over, so that the silver dispersed and fell into the flat black.

I really like how it came out. not sure if it's original or not, but a few of the AARs I've seen that were restored to "show car" status, the hoods seemed to have a bit of sparkle to them, they weren't just flat black.

this mimics that look and was cheap and easy.