Go to "Secret Codes" under the options menu and then simply enter in one of the following codes to unlock the corresponding cheat!

$EDSOC - $10,000
S1D3K1CK - $15,000
)B7@B - Die-Cast BMW M3 E92 bonus car
qlcukc4bqm - Die-Cast Dodge Charger (1969) bonus car
!C6;C>E or ""6<"?$ - Die-Cast Dodge Viper SRT10 bonus car
i3kxodepfc - Die-Cast Ford Mustang GT bonus car
!7I3JMI or !8(4*-( - Die-Cast Lexus IS F (alternate color) bonus car
0;5M2; - Die-Cast Lexus IS F Bonus Car
2<?P;G - Die-Cast Mitsubishi Lancer Evolution bonus car
?P:COL - Die-Cast Nissan 240SX (S13) Bonus Car
yp}jwa or "90=*6@ - Die-Cast Nissan GT-R (R35) Police Version bonus car
d5dviyrlgn - Die-Cast Pontiac GTO (1965) bonus car
>8P:I; - Die-Cast Porsche 911 Turbo bonus car
!2ODBJ: - Die-Cast Volkwagen R32 Bonus Car
-KJ3=E - NeedforSpeed.com Lotus Elise Bonus Car
NeedForSpeedShelbyTerlingua - Shelby Terlingua bonus car