Glass has a few drawbacks:
It's heavy, and inflexible, it also chips easy.
If you use tempered safety glass you don't have to worry about chipping because a chip will cause the whole panel to turn into little cubes....[

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Laminated glass won't shatter, but the tiny shards are a pain to clean up.
Acrylic has drawbacks as well, it scratches easy, unless you buy the kind with the scratch resistant coating.
Lexan is very flexible, but unless tied down well, or fairly thick it moves constantly and could be a distraction.
Clearly there are benefits to all these various materials as well, so the choice can be hard.
I tried 1/2" thick coated Lexan, and it worked OK, but my last iteration is 5/8" tinted acrylic screwed into the rear bulkhead using the coat hook screws.
What did you have in mind, something between the roll bars, or something that goes from the outer edges of the roll bars and fastens to them? [?]
Like 19falcon mentioned, I think I'd rather get hit in the head by a few ounces of plastic rather then a pound of glass, but that's your call. [B)]