An elongated protrusion extends adjacent and along a truck body corner in enveloping relation therewith, the corner located at the junction between the exterior side and top walls of a truck body, said protrusion having two rearwardly elongated edge portions respectively attached to the body exterior side wall and top wall, the protrusion having a rearwardly elongated mid-portion which is outwardly convex and which protrudes laterally throughout the major length of the protrusion.