I see so much bs about what works and what doesn't work for applying veil.
He is my guide from someone that actually applied it and screwed up a few times. By the way, I assume no liability for how you use this information. Use common sense and everything should go fine.
Number 1: This applies to polycarbonate plastic lenses only. I do not know if this also applies to glass but for our purposes we'll assume it doesn't.
Number 2: Buy an airbrush kit. No, it does not come out looking bad. Trust me: Using an airbrush is the best way. I have tried painting it on with a brush, foam brush, etc and it looks like crap. If you want it to look like a sexy, tinted head light with no running then use an airbrush. Do not dilute the veil with lacquer or any other substance. Spray it right out of the can.
Number 3: Preparation of headlight surface!!!! Do as veilguy said and get 3m perfect it. You can pick this up at any ppg glass shack store. There are different versions of this (based on grit) but I used an intermediate version. Not super aggressive and not super fine. Be sure to thoroughly polish the whole head light. I did mine a few times. After than i wiped it with amonia and then i finished off with cleaning the lense with rubbing alcohol. The light should now be ready for the veil application
Number 4: Buy some painters paper or use some other sort of paper and basically build a shield around the light to prevent overspray. You can use masking tape to get areas that you miss. Basically, you want to prevent any from getting on your paint. If you do get some on your paint than use ammonia to clean it off.
Number 5: Go on light!! If anyone has ever painted than they know about "tack coats". Don't try to finish the headlight in 30 seconds and one application. I personally recommend about 8-9 coats. Let the first coat tack up. Go and do the other headlight and wait a few mintues. Then start with another coat. The key is patience and common sense. If you start blabbing the veil on than it will start to run/drip. If you see this starting to happen than try to use the air from the airbrush to smooth it out. If you catch it early you can save it. Once again,the best strategy is to go light from the beginning.
Number 6: Clean your airbrush. Veil is super sticky and will probably screw up your air gun. Anyone that has ever painted knows the importance of cleaning your air equipment afterwards. I recommend using amonia as this does a good job. Be sure to run it through the gun and also take the tip off to clean.
Number 7: Don't take it through machine car washes. It may not hurt it but why risk it? I spent lots of time for my veil job so i'd rather spend 30 minutes on a Saturday washing my own car. I also avoid puting pressure washers directly on the light. Once again, use common sense here. A high enough water PSI can even remove the paint off of your car so what do think would happen to Veil............
For the license cover, I would perform the same steps if it isn't new. I bought mine new so i only wiped it with ammonia. The believe the main culprit of adhesion problems on headlights relates to wax build up. Veil guy has previously informed us of this problem.
Apparently I did something right as my original veil application still looks great months later.
I hope this helps guys.