the low pressure pull over effect of a crosswind is described by Phil here back in 2011.
http://ecomodder.com/forum/showthrea...tml#post276968
Moving or not, the affect is the same. Piling up wind pressure is not the problem, it is the delta-P on the backside.
The skirts are all about drag reduction, improving the flow around the rear tires.
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2007 Dodge Ram 3500 SRW 4x4 with 6MT
2003 TDI Beetle
2002 TDI Beetle
currently parked - 1996 Dodge 2500 Cummins Turbodiesel
Custom cab, auto, 3.55 gears