Bob sez.....
>the jolts.  Military 'off-road' equipment such as tanks (!) use a combination
>of centrifugal and labyrinth principles.  The centrifugal filters are either

The vanagon Syncro uses the passive centrifugal setup in conjunction with a 
'normal usage' (cheap) or 'dusty usage' ($$) disposable paper filter.  Nice 
to lift out the centrifugal trap and pour a small handful of fine powdery 
silt out. And I just drive dusty logging roads, no Baja!  The unit can be 
retrofitted to any vanagon, it includes a 'snorkle' that goes way up the 
side vent duct to get above the dust a bit.  BFG's Baja Commanders, better 
breathing and some VW-AG underbody plates would make a good upgrade to 2WD 
vanagons going desert bashing.
Tim Smith