Dust Problem On Dirt Roads

I have a 1998 jetta...
I was wondering if anyone has ever experienced a lot of dust if they live on dirt roads or happen to drive on them...
I have tried the the different vent controls but still There is alot of dust, and also seems to be dust in the back door jams...could someone help me out please.

I used to rally race in my Montero/Pajero/Shogun. I also used to rally in a Subaru and I live around alot of dirt roads. I can tell you this much, it might hurt performance, but add/do these things...

1. New door sealing
2. Rally style Mud flaps
3. Check your filters, all of them!

and also check cockpit pressure. Find a gas you can expel from inside the car while your outside, a colored, but not dyed gas, and release the gas in the cockpit. Stand outside and watch for the leaks. Those leaks should be patched, which will net a more positive dust control. Dont bother with the air adjustments because they flow through a filter so no dust gets in any way you adjust.