There is a track up in Dayton, OH where they do the figure 8 school bus races.  My brother's friend entered one year.  He made it through the figure 8 race, but didn't finish the school bus demolition derby.  His radiator failed him.  One guy in the demo derby was playing possum.  He turned his bus off about 2 minutes in, then with about 2 minutes left, he fired up the bus and came in second