you can do some work at the front to fair the cab onto the nose of the trailer. The new ones are very nice aero, but the crosswind still gets in there and wreaks havoc. It is "low hanging fruit" to use an aerohead phrase
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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