Play a regular game. When you finish and return to the title screen, press C
to enter the Options screen and set the game to Practice. Hit B and C,
then press Start to exit the menu and Start the game. You'll be practicing
with the traffic of the regular game!
If you can't beat the Phantom on the stunt track then beat him on the
speed track. In the championship lap, turn Right instead of going straight
ahead. You'll pass over the turn signs and find yourself battling the Phantom
on the speed track!