Lexus headlight plastic does not have any special UV coatings that wet-sanding will remove. Maybe some other companies do, but Lexus does not. Headlight plastic is approx 1/4 inch thick; there plenty of opportunities to wet-sand without going through... If you did the procedure once a year for 10 years you'd still be fine. Well worth the results in my book.
I've done quite a few headlight retrofits. I know what coating you're speaking of, but it's not present in Lexus. After completing a retro i do a complimentary wet-sand and polish for my customers. I know the headlights with this 'coating'- it's quite hard to sand through. Lexus, not so.
You are correct, Sorry, I forgot... Thanks for the correction.