I've found that going along dry gravel/forestry roads at speed I get a huge amount of dust coming in. It's not as bad when on tight trails at lower speeds. I can control it a bit by raising my windshield (Honda OEM) as far as it will go so the wind comes in and breaks the vacuum effect that sucks the dust in behind you. At least I think that's what happens. Does installing a rear window help at all or is it a waste of money?