MSHAVER: The Internet returned this answer to your question:
"There are primarily two types of safety glass.
"Tempered glass is used to create entrance doors and other components in commercial buildings. It’s also used in vehicles as door, vent and back glass. During the manufacturing process, tempered glass is heated to over 1,100 degrees. It’s then shot with cold air, which forces the glass to cool very rapidly. That process causes the outer surface to become much harder than the inner material. As a result, tempered glass shatters into tiny fragments with rounded edges when it’s broken.
"Laminated glass is used primarily for vehicle windshields. Two sheets of glass are bonded together by a plastic inner layer known as polyvinyl butyral. The inner layer softens the blow when anything hits the windshield and prevents the glass from separating. That, in turn, reduces the chances that you and your passengers will be seriously cut in the event of an accident."
Unfortunately, I've busted out one Kubota RTV900 windshield. It musta been laminated, 'cause it exploded into a gazillion pieces, but they were all contained in slabs of broken glass held together by the plastic inner layer. So ... I think laminated is the way to go.
Plastic: no. First, it's going to scratch ... no matter how careful you are in using plastic cleaners and proper wiping procedures, it's gonna scratch. And it's gonna fog over in certain weather conditions, and when you wipe off the fog ... scratches. It's gonna get frost, snow, or ice on it, and when you try to scrape it ... scratches. You're gonna drive through the woods and tree limbs and branches are gonna smack the windshield ... scratches. Over time, the plastic windshield may get hazy from the thousands and thousands of scratches, scars, gouges, and other indignities it will suffer ... scratches.
Plastic works fine on my motorcycle windshields and helmet face masks. I use Novus plastic cleaner and it takes out all (or most) of the fine scratches. I also use Plexus Plastic Cleaner ... get it from Amazon.com or just about any motorcycle dealership. It's good stuff and easy to use, but still ... scratches happen.
I have the metal frame from my busted windshield. If you have access to a glass shop that can do custom work, you might could get them to cut a glass for the frame. If you're interested, we can probably do a deal. Shipping would be a royal PITA because of the frame's size and weight.
Good luck with your decision. I hope you enjoy your 900 as much as we enjoy ours. Happy New Year.