I think the company name is VHT and its called Dark Shades. Its like a spray paint that is translucent thus making it a tint spray paint for your taillights or headlights for that matter. I got it from Ramchargers but im not sure if that chain is national or not.
I bought that VHT stuff from summit a while back and did my tailights. I like it to break up the red on my lazer red car, Used to get a lot of compliments (probably still would if it came out of the garage more often) but now I need to repaint and re-do tailights (im picky)