My understanding is that the thickness of the windshield is a function of the brand of glass, not the year of the car (this from a buddy who managed a SafeLite glass shop for a decade and advised that I NOT buy SafeLite glass for my brick).

I have read here that the later '91+ glass is more desirable. The glass itself is bigger and it uses a simpler trim gasket that is less prone to leaks and rust around the windshield. It also gives the earlier cars a more updated look (as if that matters now that they are all 15+ years old!)