Abstract: 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 trailers in tandem and vehicles towed by cars. The drag reducer can take the form of a fin mounted rigidly or with articulated joint or flexible material to allow for movement between the leading and trailing vehicles. It may also be of a retractable nature, such as an accordian arrangement, a roll-up screen, an inflatable fin, a folding plate, etc.