What type of "paint" are you talking about? Rustoleum or automotive paint?
If it's Rusto, I'd say just clean them, scuff, prime and paint a few topcoats.
If it's automotive, I think you'll need to consider flexibility, which is where your rustoleum is probably going to have a problem, and definitely consider whether the auto paint will eat the plastic that these things are made out of. (I melted a helmet shell one time from using the wrong type of paint.)
On the other hand, if you use Rusto, you can just repaint them if they start looking flakey.
One more thought, which might address the flexibility is to potentially use dashboard paint - never tried it tho.