Discussion: Dust Proofing Your Caravan

I am about to purchase a Paramount Duet Pop-up Expandable Caravan, and would like to know if anyone has ever installed a 12v fan with a filter in their Caravan to help pressurize the inside of the van to minimize the dust problem? If not, has anyone got any suggestions? We plan to tackle the Great Central Road in July next year and would like to solve this problem before we go. Any help would be appreciated.

Kevin, WA