At the main menu, hold Select and press L1, Left, L2, Right, L2, Left, L1, L1.
School bus
Select "Single Race" or "World Tour" mode. Then at the transmission selection screen, hold Select and press L1, Up, L2, Down, Down, L2, L2, R2.
Ice cream truck
Select "Single Race" or "World Tour" mode. Then at the transmission selection screen, hold Select and press R2, L2, L2, Down, Down, L2, L2, R1.
Black widow truck
Select "Single Race" or "World Tour" mode. Then at the transmission selection screen, hold Select and press R1, L2, L2, Down, Down, Up, L2, L1.
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.