Cheats for NASCAR Rumble on PS1.
From the main menu go to Game Options, then go to Load and Save and scroll across to change it from Memory Card to Password, then press X. Enter one of the following passwords to unlock the corresponding cheat effect:
Unlocks all tracks and Pro cars.
KMZWA8AWAA or KMZWAY87AA
Unlocks everything – all cars & classes, all tracks, all difficulty levels, and a hidden Grand Champion video in the Showcase menu.
Unlocks everything except for the EA Sports car.