At the title screen, enter the Test Run menu. Now, highlight "Start", hold Left + II and press I. If done right, the computer will control the car.
Bad Ending
At the password screen, place the cursor at the start of the last password row. Now, enter following password: ONOZAKI TAKESHI.
Get the Auto CPU Mode in World Championship Mode
Enter your name as AAA.
Good Ending
At the password screen, place the cursor at the start of the last password row. Now, enter following password: MASUDA MASATO.
Sound Test
At the password screen, place the cursor at the start of the last password row. Now, enter "TESTA" and hit end. If done right, you'll get the sound test menu.