Its spray glue + feathers on a stock wedge. So most of the "work" was in the idea, I guess. We would apply spray glue to the underside of the feathers, apply them, and then cut the ribs free. The latter operation required the box cutter - so I had to do that for him. But I have seen instances ( not kidding ) where daddy used a CNC mill to shape the car, then apply a professional auto paint job.... so all things considered....
It was, ahem, not the fastest car. But we did take "best scout theme" primarily because it was the only car to reference scouting in any way. ( sigh ) To be honest, I have seen the least aerodynamic designs win. There was one year the winning car of 40+ cars had a 6" tall plastic palm tree glued to it. I think NASA should investigate.
I think part of the issue was the tires rubbing on the spray glue coated feathers? Mabey? Ha! LOL! ( And I never say "LOL." )