After selecting your team, enter the "Course" option. Once inside, hold II and press I to go back to the Team Select screen, but this time all teams will be available.
At the Team Select screen, hold II and press I.
Start the game and input your name. Place the cursor on the End icon (running man), hold Select and press I. If done right, the ending will start right away.
At the title screen, hold Up + II + I and press Run. When you start the race, you'll have a different type of car.