Aerodynamic drag reduction devices for surface vehicles

In combination with a truck that includes a cab having a roof, and a box-like body elongated rearwardly of the cab, the body having an exterior front wall facing forwardly toward the cab, said front wall extending downwardly substantially below the lever of the cab roof, the body also having laterally opposite exterior side walls, and an exterior top wall, each side wall meeting said top wall at a rearwardly elongated corner, the improvement that comprises,

• a. an elongated protrusion extending adjacent and along one of said corners in enveloping relation therewith, said protrusion having two rearwardly elongated edge portions respectively attached to said body exterior side wall and top wall, said protrusion having a rearwardly elongated mid-portion which is outwardly convex and which protrudes laterally throughout the major length of the protrusion.