During a race, pause the game, then hold B and Select. After, pressing A will increase the "lap timeout" variable: it is one invisible to the player; however, increasing it will allow you to stay on a race as long as you need without automatic retirement. (Note: Incrementing the timeout too high will cause an automatic timeout.)
At the title screen, press A, B, A, A, A, B, A, A. If done right, a sound will be heard.
After a "Game Over", enter the following code and select "Continue".
During gameplay, pause the game and hold Up and A, then unpause - this will boost the car's speed to the maximum, no matter what your prior speed was.
Enter the following passwords at the CONTINUE screen. be sure to enter your name as "AETHER-K" or the passwords won't work...