i have a soft tonneau and just throw stuff in there pretty much. i try to put it in totes or containers or something, not completley water tight but its good enough. its a truxedo low pro qt

 

Pretty dang near water tight in all but high pressure car washes and monsoons I think. I never saw water under mine when it was on the truck. Had I known then that the LoPro could take snow weight so well and that I'ld have a carport to park her in during heavy snows, might have kept it on the truck. Damn nice covers!