Start game, go to the main menu, go to the Statistics sub-menu, go back again (pressing DELETE),and enter your cheat.t:

111skyline - unlock Skyline
119focus - unlock Focus
221miata - unlock Miata
222lancer - unlock Lancer
334mygolf - unlock Mygolf
350350z - unlock 350Z
371impreza - unlock Impreza
667tiburon - unlock Tiburon
777rx7 - unlock RX7
77peugeot - unlock Peugeot
893neon - unlock Neon
899eclipse - unlock Eclipse
922sentra - unlock Sentra
gimmeppablo - unlock Petey Pablo
gimmesomecircuits - unlock Circuits
gimmesomedrag - unlock Drag Circuits
gimmesomesprints - unlock Sprint Circuits
gotcharobzombie - unlock Rob Zombie
havyamystikal - unlock Mystikal
needmylostprophets - unlock Lost Prophets

 

PSII CHEATS

Type in the following codes in the main start menu:

right, square, left, R1, square, L1, L2, R2 - unlocks all drag tracks

left, left, left, left, right, R2, R1, L2 - unlocks all drift tracks

down, R1, R1, R1, R2, R2, R2, square - unlocks all circuit tracks

up, R2, R2, R2, R1, down, down, down - unlocks all sprint tracks

X, circle, triangle, triangle, X, X, circle - unlimited nitro