All cars and tracks:
Hold Select and press L1, Left, L2, Right, L2, Left, L1(2) at the main screen. A squeak will confirm correct code entry.

School bus:
Select "Single Race" or "World Tour" mode. Then, hold Select and press L1, Up, L2, Down(2), L2(2), R2 at the transmission selection screen. A squeak will confirm correct code entry.

Ice cream truck:
Select "Single Race" or "World Tour" mode. Then, hold Select and press R2, L2(2), Down(2), L2(2), R1 at the transmission selection screen. A squeak will confirm correct code entry.

Black Widow truck:
Select "Single race" or "World Tour" mode. Then, hold Select and press R1, L2(2), Down(2), Up, L2, L1 at the transmission selection screen. A squeak will confirm correct code entry.

Nitro car:
Select "Single race" or "World Tour" mode. Then, hold Select and press L1, Down, Up, L2(2), R1, Left at the transmission selection screen. A squeak will confirm correct code entry.

View programmers:
Select the reversed Mojave track for a race. Start the race, then turn around and drive in the wrong direction at the beginning. Go to the right of the sand dune and keep driving in that direction until finding the Accolade sign with the programmer pictures.