At the Options menu, hold L1 + R1 and press X, X, X, X.
Brick Car:
At the Options menu, hold L1 + R1 and press Triangle, Triangle, Square, Circle.
Flat Characters:
At the Options menu, hold L1 + R1 and press Circle, Circle, Circle, Circle.
Burns' Limo:
At the Options menu, hold L1 + R1 and press Triangle, Triangle, Square, Square.
Nuclear Bus:
At the Options menu, hold L1 + R1 and press Triangle, Triangle, Square, X.
Time Trial:
At the Options menu, hold L1 + R1 and press Circle, Triangle, Square, X.
Night Mode:
At the Options menu, hold L1 + R1 and press Circle, Triangle, Square, X.
Barf Cam:
At the Options menu, hold L1 + R1 and press Triangle, X, X, X.
Halloween of Horrors:
At the Options menu, hold L1 + R1 and press Triangle, Triangle, Circle, X to unlock Bart in a Frankenstein costume. Alternately, set your PS2's internal clock to October 31.
Happy New Year:
At the Options menu, hold L1 + R1 and press Triangle, Triangle, Circle, Square to unlock Barney in a tuxedo. Alternately, set your PS2's internal clock to January 1.
Thanksgiving Time:
At the Options menu, hold L1 + R1 and press Triangle, Triangle, Circle, Circle to unlock Marge as a Pilgrim. Alternately, set your PS2's internal clock to the third Thursday in November.
Merry Xmas:
At the Options menu, hold L1 + R1 and press Triangle, Triangle, Circle, Triangle to unlock Apu in a Santa costume. Alternately, set your PS2's internal clock to December 25.
Disable all codes:
At the Options menu, hold L1 + R1 and press Start, Start, Start, Start.
Hidden Car:
Beat all 10 missions, in mission mode to open ''Homer: The Car built for the Average Man.'' Just click on on Homer's picture in the car selection screen.
Gain Extra Time:
While driving in Road Rage mode, hit any of the "bus stop" structures and gain an extra 2 seconds every time you do this. This could become crucial in those deliveries where you "just miss" by a second or 2.