John that great, It gets me excited just hering of the race. As I mention !11 plus yrs. donated time. And that`s the correct answer
Size, all 4 wheels and nails [use nail slot provided] no wet lub and no there is no lemit on amout of graphite. %oz.. The scout car should be builded by scouts and within the guild lines. Imagine your son wins, and than is disquilfied because you "needed more power" [Tim]
But mostly if you have a non-scout competition it keeps those that can`t help them self and mess with the kids cars at bay. Plus those deprived adults that didn`t get to play when they where tots!

Our non scout comp included the girls and those to young and old. Than we put them againt top scout cars, all just for fun.