Had a good long, hot gravel road ride yesterday. This rear window thing is pretty cool. I run the half windshield. I was the second in line, and got my fair share of dust. I was dusty, but it's not like it was swirling in the cab. And I had good air flow. Haven't had the chance to look at the filter, but the inlet area doesn't show any real signs of excessive dust. So far, I'd recommend this.