Testor's transparent black model tint (available at hobby shops)
Testor's gloss enamel clear coat
1. Sand the outside of the lense to be tinted until there is no gloss left. You want a dull finished surface since the testor's paint likes to run a lot.
2. Mask off any part of the light you don't want smoked
3. Start by spraying thin coats, use the blowdryer in between coats to speed up drying time. When one coat gets tacky, spray the next.
4. Keep applying coats of the transparent black until the desired result is reached.
5. Start spraying thing coats of clear, applying the next coat when the previous coat gets tacky. Again use the blowdryer to speed up drying if you are impatient like me.
6. Wetsand if you so desire. A little rubbing compound can help shine up the finish as well.
You are done..
Pic of what mine looked like on my old jetta..