I put two ammo cans in the bed of my truck to carry tow straps and stuff that might be too dirty to put behind your seats. No drilling at all. I used those big drain holes found in the bed of doublecabs. I used a bolt, some large washers, and a wing nut to attach the ammo cans. In case you ever have to take them out in a hurry, you just take everything out and take off the wing nut and there you go. Of course they are not theft proof, but I don't put anything in there I can't replace. Great for the trail.