Jarrett and Labonte Stock Car Racing cheats, and Codes for PSX.
Get to the code screen by selecting "Options" from the Main Menu, and then going to the "Bonus" screen. At the Bonus screen choose the :Enter Cheat Code" option and then enter the following cheats from the list below.
As you enter cheats, you should see them listed on the Activate Bonuses screen. Note: The codes don't work in Championship Mode.
To unlock cars, you have to collect a minimum number of points in Championship Mode, according to the table below: