I meant to add two more things also:

I would have to guess there are different types of Lexan, or perhaps different coatings on them like was mentioned above. I've never tried to polish out Lexan on a car, only on motorcycle. I don't even know if all of the motorcycle windshields I've polished were Lexan - I only knew on this one because it said it was. So I'm not disputing what Mike said, I'm just adding my feedback from a motorcycle windshield standpoint.

The second note is, I can also tell you that, even though/if Lexan is also used on headlights, Meguiar's Keep Clear Headlight Coating is difficult, maybe impossible, to spray on clear enough to use to replace the coating on a motorcycle windshield. Just saying. (Nothing ventured, nothing gained, and it buffed off with M105).