F-1 World Grand Prix
Broadcast Mode
Choose the television camera as a driver to use broadcast mode.

Infinite Fuel
Select "Grand Prix" mode and enter the paddock screen. Set your car's fuel level as low as possible, then start a race. Infinite fuel will now be available on the next race.
Credit Goes To: bLacKhAwK via N64cc
 Broadcast Mode
 Infinite Fuel
 All Challenges
 Bonus Track(2)
 Gold Racer
 Silver Racer
 Team Extreme
 Bonus Track
 Credits & Gallery
All Challenges
Highlight Driver Williams and change his name to Driver Pandora. Then select challenge as your mode and enter file 4 (it should say cheaters special).
You now have access to all of the challenges including the ultimate one.
Credit Goes To: bLacKhAwK via N64cc

Bonus Track(2)
Go into Exhibition mode and select Driver Williams. Using your Control Stick, edit his last name to "Vacation." Exit all the way to the Start screen, then re-enter. You'll find a bonus track after the European Grand Prix. This Hawaii track winds past palm trees, over a gigantic suspension bridge and even through a volcano.

Gold Racer
Go into Exhibition mode and select Driver Williams. Using your Control Stick, edit his last name to "Pyrite." Exit all the way to the Start screen, then re-enter. A new Gold Driver will be available in Exhibition, Time Trial and 2 Player modes.

Silver Racer
Go into Exhibition mode and select Driver Williams. Using your Control Stick, edit his last name to "Chrome." Exit all the way to the Start screen, then re-enter. A new Silver Driver will be available in Exhibition, Time Trial and 2 Player modes.

Team Extreme
Achieve 100% skill level in the Challenge Mode, and it opens the credits option on the start screen as well as revealing the silver and gold drivers from "Team Extreme" in Exhibition, Time Trial, and Two Player mode.

Bonus Track
Beat the championship on professional and a bonus track will open.

Credits and Gallery
Win the championship on rookie to unlock two new options at the start screen: gallery and credits.
Credit Goes To: IGN 64