Clear paint on heaflight turnrd white. Think i am screwed.

IMH If you are going to bother to clearcoat anything, use '2k' paint with a hardener. Look for the ones with the activator button on the bottom. About 20 a can on amazon. Used on everything from brand new wheels, to buffed out headlights. Only had issues once when i forgot to buff out the polish first, came out slightly hazy. I usually do a polish after a few days. 303 is what I use in the meantime for newer headlights. I have had great results with Novus plastic polish for medium scratches, and acetone for deep ones. Once the outer .2mm is affected, I always seal it. Ymmv. 

I have done teh brake cleaner trick many times.  I always try it first.  I am not sure if it removes or relocates the plastic but when it works it works great.  On other headlights it has absolutely no effect at all.  I suspect that it is a different plastic.

The thing is if you are willing to use power tools for the sanding and buffing it really is about a 15 min job.  Sanding and buffing by hand sucks and take 4x as long.  Just make sure you put a good couple layers of tape around them so you don't get the paint.

I didn't see anyone mention this, but nevermind that it says to test in an inconspicuous area.  More importantly, nowhere on the can does it say it is intended for any type of plastic.  At least start with one of the cans that advertises itself as being meant for plastic.

The plastic used for automotive headlamp lens is polycarbonate (PC). It is attacked by toluene and acetone causing the crazing you saw.  It is very tough and impact resistant but is soft and not the most weather resistant. The headlight manufacturers apply a silicone hard coat to the injection molded lens to increase scratch resistance and slow down the UV weathering.