GP-1 Rapid Stream

When the main title "GP Part II" comes out, but before any music heard, Hold L+R button on Controller 2, and press "Start" button on Controller 1. The screen will changed to dark with only "Sound Test" text appear. To choose the music, tap the D-pad left or right to make the music titles appear. To plays the music, just tap B or A button.

A the title screen, select GP Race, then enter the following passwords at the Continue screen:

To get speed boost at the beginning of race, just try to make the speedometer's needle-hand pointing at the line between number "8" and "10" when the green light's up. If you time it correctly, you will get extra boost which may passed all the opponents when the racing just starts. This trick is working almost the same like Speed Boost trick in Mario Kart.