All racers:

Press Circle, Triangle, X, Circle, Triangle, X,
Circle, Triangle, Square, X when the Muppets are
racing over the logo to unlock all 24 main racers.
A message will confirm correct code entry. 


Unlock The End and six overhead tracks: 

Press Circle, Triangle, Square, Triangle, X, 
Triangle, Square, Circle, Triangle, X when the
Muppets are racing over the logo. A message will 
confirm correct code entry.