A pickup truck cap having bendable plastic side panels having a bottom side located along a respective riser installed on each pickup truck cargo bed side wall. The side panels are each engaged by a curved respective guide located adjacent each end of each side panel to conform each side panel to curvature of an associated guide. An upper side of each side panel is received beneath a rectangular top assembly included in the cap. Either of side panels are movable upwardly to raise the bottom side thereof up from a respective riser to create an access opening beneath a raised side panel along each side of the cap. A pair of movable side panels can also be arranged to close off access through a cover installed on the cargo bed of a pickup truck.