I've always got a jug of diesel additive in my van, which, almost never seals well and if i keep it inside usually spills a bit. that, plus for longer trips i'm looking to carry some extra oil. I'm trying to think up ideas to carry my additive, oil, or whatever else on my rear bumper. I've got two swing outs, one with a sideways mounted jerry can holder, one with a tire. pretty basic bumper besides that. was thinking of mounting an ammo can to the jerry can holder, but wanted to see if anyone had some ideas before i commit.