The front windshield creates a vacuum behind it so that sucks the dust in. Anything you can do to move air inside the cab will help break up the vacuum and blow the dust out. Vents or even better a roof fan is about the only way to control it to something manageable. I just run a half windshield in the warm months and then a full enclosure when I run a full windshield during the winter. I have seen some desert guys running a roof fan and that seems to work for them. Hope that helps!

 

We run a half windshield in the SW deserts and it works for us. It cut the dust by about 3/4 but at the end of a long day, you're still dusty.

Best thing we've found is to not follow too closely.

 

Also in the dusty desert, I ran my ‘16 XP4 1000 with a half windshield for a few years and resigned myself to the inevitable dust bath by the end of a ride. I had some sun visors that I used to deflect air onto my nose & mouth so it was never bad enough for me to change anything.
Day 1 in the Pro XP 4, half windshield, was a real eye opener....or should I say closer. It sucked dust up from everywhere and intensified with more throttle. I tried the rear window, full doors, the 1/4 windshield and some homemade wings to deflect air down at the rear and sides. Slight improvements but it was still nasty. Finally, the temps warmed up into the 70’s (yes, I’m a spoiled wimp) and I took the 1/4 windshield, wings and rear window off and went with full air through the vehicle. Finally, I don’t feel dust in my eyes and throat and it’s a huge improvement. I should mention both of my 4 seaters had/have an aluminum roof installed.

 

We've ridden a lot of trails in our Jeep Rubicon with the windows up and the Heater or AC running. Weeks later you could turn on the AC and dust would blow out. Later Jeeps have a cabin air filter but they plug up.

It is a dusty sport. We've learned to accept it in exchange for time with family and friends along with seeing a lot of beautiful country, old mines, petroglyphs, etc, etc, etc. Wouldn't trade it for anything.

 

Custom make yourself a rear windshield out of plexiglass and zip tie it to the bars.

even if it doesn’t seal well, if it can knock down a significant portion of the airflow, it will make a big difference.