Abstract: For a modular pickup bed cover system having a plurality of rigid transverse panels which slidingly fit into longitudinal channels fixed along bed side walls, interpanel latching is provided by a transverse, channel-shaped first latching member fixed across rearward ends of all except the rearmost panel and a matching, transverse, angle-shaped second latching member fixed across forward ends of all except the forwardmost panel. Fixed across the rear panel of each panel pair in panel abutment regions is an elastomeric seal. As each pair of panels is latched together, upon installation thereof into the truck bed side channels by pivotally fitting the rearward panel angle member into the forward panel channel member, the seals are compressed a preselected amount assuring weathertight interpanel sealing. Shaped end regions of the latching members cause transverse panel alignment during latching.

Abstract: A pair of rails mounted on top of the sidewalls of a pickup truck bed, with each rail forming a channel with a slot at the top, to receive mounting feet of accessories. One accessory is in the form of three cover sections with mounting feet received in the channels, and with cover sheet portions that extend beyond the slots and down to at least the rail height to prevent the entrance of water into the truck bed. The rearmost section has a depending flange which lies below the level of the tailgate, so that when the tailgate is locked up, the accessories cannot be removed. When the sections are locked in their adjoining relationship, a U-shaped elastomeric member and a trough enable a complient, elastic seal between adjoining sections. The cover sections may have sidewalls of substantial height to allow use of the truck as a van or camper.