A vehicle rack system includes elongate structural members coupled together to form a rack for use on or within a vehicle's cargo area. At least one of the elongate structural members has an elongate pressure tight lumen for holding a fluid therein, and a nozzle allows the fluid to enter and exit the lumen. A vehicle having a rack system includes a vehicle and a plurality of elongate structural members removably coupled together to form a rack removably coupled to the vehicle. A first of the members has a longitudinal slot between and behind a pair of flanges. An anchor is positioned in the slot, and the anchor is irremovable from the slot while the system is at an assembled configuration. The anchor is removable from the slot while the system is at unassembled configuration. The anchor is used to secure the first member to a second of the members.