Ammo Can Saddle Bags

[Quimrider]

I finally got around to painting my ammo cans. I painted them a dark Charcoal/gunmetal color. My friend has a sign shop and has some reflective silver vinyl. I want to use that to increase visibility. Anyone got a suggestion as far as what kind of graphic I could make for these? I initially thought of a skull and cross bones, but I thought that would probably look silly.