I used to have a pic on my website of a DC-9 center cockpit window that was shot with a Tromix 50AE and the bullet blew the crap out of it. Punched all the way through. I also shot one with a 440 CorBon and a .458 SOCOM with the same results. The glass is 2.5" thick of three plys of laminated glass.
Hit with a .223, it just takes a little chip out of the glass surface like it was hit with a BB gun. That was with a 55gr FMJ bullet. Maybe a 70+ grainer would fare a bit better, but I doubt by much.
A .223 against thick glass is horribly shitty............sorry. ;-(
Lexan is polycarbonate and is like a soft pliable transparent plastic. It works best laminated to the back side of glass to keep glass shards from blowing out the back side. The glass absorbs the energy and the polycarb keeps the little pieces from blowing out the back. Alone, Lexan will get punched through, no problem.
Autoglass is pretty thin, so if it isn't hit at an extreme angle, a .223 will probably go through without a problem, though I have not tested it.
Tony Rumore
Tromix Corp