There are a couple different products that you can use, depending on the application. Are you tinting some lights?

You can buy model paint that is a transparent black. I think it's called 'Window Tint' by Testors.

Otherwise there is a product called Niteshades, and some other knockoffs that you can usually get at larger autoparts stores.

 

Try here . Scroll down to "Smoke Color Lens Spray"

 

i bet youre gonna paint the inside of the brake lenses of your maxima. i would too.

 

When you find transparent black, can you get me some dehydrated water, too?

 

lol