A drag reducer for a gap in a land vehicle moving through air which consists of a retractable or articulated baffle, spanning approximately the entire distance of the gap. The drag reducer can be used on all land vehicles and is readily adaptable for use on railroad box cars, truck semi-trailers, full...http://www.google.com/patents/US4257640?utm_source=gb-gplus-sharePatent US4257640 - Drag reducer for land vehicles
