I don't have any black, so I left it out. Glow in the dark for the white parts on the small set. Then I figured . . . supersize (250%) Kevin, put magnets on the back (lots of magnets) and attach it to the back of the car. Unfortunately I wiggled the printer changing from the red to white filament so it shifted. Still works.
After I increased the size to 250%, I decreased the thickness so It wouldn't take forever to print (as is, took a little over 3 hours).