Are you talking about the hard rear window?? If so how good does it work at keeping stuff out?I'm runnin the clear window, it's ok but there is only one mount point at the center bottom. If you trailer it down the road it fills up with air like a parachute and tears at the bottom! Solution was a full strip of Velcro along bottom.
What about on some of the wet trails/ dirt roads, does it gets any spray from the back on the interior and your arms?? My buddies commander did but he had nothing in the rear window area..I think he is talking about the clear soft window. I had a hard window on the back of my rzr with a hard roof and windshield and, it kept everything out. Like i said above i have to windscreen on my mav. Also have a hard roof and windshield and, i haven't got anything inside it either but, i haven't really been on many dusty conditions yet since there has only been snow on the damn ground still.