Hidden in plain sight.
It's fun to put myself into my work. Often I sign my work, but always in a subtle way - sort of. In the case of the dump truck we are working on the most obvious place (and the best place to hide it in plain sight) would be top center of the grill. The truck will sport a 'D' on the emblem - just for fun. Most who look at the truck will find an emblem in this location perfectly normal and most likely not even see it.