cool story - but that still doesnt solve my problem

 

Stick the decal to one of those magnetic photo stickers (most stores like Walmart, Target, or any office supply stores sell them for a few dollars or so. Pick up one or two high powered magnets (hardware store).

Stick the decal on the magnetic sheet. Remove one of the tail lights or go from underneath (both are easy) and hold the high-powered magnets on the inside of the bumper cover. Slap the now-magnetic decal on the outside of the cover... viola... at least it sounds good in my head.

 

Trunk, side panel, fender and roof are steel.