While my dirt driving with a van has been just outback QLD, I did find once I had gone over my van with sealant in hand, added some vent flaps I had kept the dust at bay, most of my dust was entering via the rear wall pod which was poorly sealed. My idea for drawing air in was from the side of the van, but didn't need to follow thru with it.
When I drove a truck out there it had a system where the air was filtered, I found 2 x triple road trains driving by I would need to clean the filter and it was a huge thing......
Be great to see your pics on the road.