To my eyes they sort of look tinted anyway. Then there are potential legal/insurance/safety issues, etc. But if you like it and are prepared to take the risks, then go for it (probably a spray-on tint would be easiest).
Jack Travis, E-Series Acting President
1989 Ford Fairmont Ghia turbo/GL replica (underway)
1994 Eunos 800M
1990 Ford Laser S