SEM calls for about two minutes per area with their own light which is about 3 inches. So, figure about 6 minutes per headlight. Since I couldn't afford their light ($200+), I just got my plain old black light bulb and left it in each spot for a few minutes and kept scooting down as I was doing other stuff. I think it ended up being half an hour per headlight. I wasn't paying attention. Other people say just to leave it in the sun all day and it'll cure fine. Curing is not the same as drying.
Some people get all scientific and argue about UV wavelength from the SEM light is proper while UV lights from Spencers or Home Depot aren't as good but I just know I didn't have a bunch of money for a lightbulb.
There are other methods as well. Here is one I've looked at before and was impressed with his before and after photos:
http://www.autogeekonline.net/forum/...lant-idea.html
ive restored a couple headlights via clay, polish w/ a cutting pad, and wax/sealant.
instagram >>> @cmxciii
no moar miata. i just lurk & stuff now.
I have used 3M's product before and loved it, my old jetta had horrible lights and after using it they looked brand new. My friend who helped me do them has done them to all of his cars and loves the product aswell, I havnt had the car I used it on for long enough to tell if it works well after a long period of time but I probably had a total of 5-6 months after using it and they looked just as good as the day I did it.