There's also actual lens tinting. I'll pull some things off NWH for that too.
"Ever wanted to shade (or tint) your tail lights, or any other lenses, but just didn't know how, or didn't want it to be permanent. Well there's a cheap and easy way to do it.
Materials Needed: * Axius Windshield Tint Strip (i found at Wal-Mart for $3.00!!! ) * Credit Card * Razor Blade
Time: *Depends on Application (my bumper lenses took 1 min. )
Directions:
First clean the lense very well. Then cut out some of the tint for the lense. Apply tint by using a credit card to the lense. using the razor trim off the excess tint. Ta-DA, all done "