Knight Rider

Level select:
Hold A + B, press reset, release both buttons, then choose the "Mission" or "Drive" option. Press Up or Down when Devon appears to select the starting level. Press Start to begin game play at the selected level.

Boss battle, weapon select:
Press Start to pause game play. Then, hold Up/Left + A + B and press Select to change weapons. Press Start to resume game play at the Boss of the current level.

View ending sequence:
Hold Select and reset the NES.

Secret message:
Hold Select + Start and power on the NES.

Desert Battle level:
Enter NSMRNQIUKRISD as a password.

Super car:
Successfully complete all levels in driving mode at least three times. After returning to the menu screen, select mission mode. You car will be equipped with all missiles, lasers, full engine speed, and other bonuses.
Information in this section was contributed by KNIGHTRCER.

Hint: More time:
After the timer expires, keep pressing Turbo to keep moving. If you have enough turbo and keep your speed over 0 mph, you may be able to reach a Boss and continue the game.
Information in this section was contributed by jcrum.