same as above, my personal tundra has one, and my work truck has one. Both have ARE caps. I wouldn't use it without a cap, BUT since i have them they arn't going anywhere.
Tundra - camping gear, food weekend supplies (hammock knife axe) and recovery gear and tools on the other side.
F-350, soft goods on left (computers/scanners, fuses, tow straps), tools on right side, however, most of the rest of the bed is tools and climb gear also
I will say, 4 tires barely fits in the bed of a 6ft F-350.. and a Kubota 520 tire forget about. I couldn't haul a 3ft long piece of 28'' corrugated pipe the other day......
SO how often do you haul bigger stuff.