Based on the plastic model kit from 1968 by famed car designer Tom Daniel.
From the model description:
Inspired by the infamous German 'Ace' of World War I, this madcap creation is the hit of the show-car circuit! Powered by a vintage Mercedes-Benz aircraft engine with six 'trumpet' exhausts, it's got a custom interior you've got to see to believe. But don't get out in front of those side-mounted machine guns. The German Iron Cross shows up on the 'alloy' wheels as well as the sides of the giant, plated, spiked helmet.