I'll give you them.

Unlock ALL Cars:
Enter YAYCARS as a code

Unlock ALL Races:
Enter MATTL66 as a code

Unlock ALL Paint Jobs:
Enter R4MONE as a code

Unlock Super Fast Start:
Enter IMSPEED as a code.

Unlock Infinite Boost:
Enter VROOOOM as a code

Unlock ALL Tracks and Mini-Games:
Enter IF900HP as a code

Unlock Maters Speedy Circuit and Maters Countdown Cleanup:
Enter TRGTEXC as a code

Unlock Drive on Fire:
Enter TORCHED as a code

Unlock ALL Movies:
Enter WATCHIT as a code

Unlock ALL Concept Art:
Enter CONC3PT as a code

Race as #33 Race Car:
Enter DUN33LI as a code

Race as Boost:
Enter CHEATER as a code

Race as DJ:
Enter MUSIC8R as a code

Race as Fillmore:
Enter PEACEOT as a code

Race as Fletcher:
Enter RACEKAR as a code

Race as Lizzie:
Enter OLDY2D0 as a code

Race as Luigi:
Enter CASEDEL as a code

Race as Mia and Tia:
Enter MCQNL94 as a code

Race as Sarge:
Enter BOOTCMP as a code

Race as Tractor:
Enter FRANKSB as a code

Race as Woody the Wagon:
Enter PIXARFY as a code

Race as Monster Truck #1:
Enter MONAR02 as a code

Race as Monster Truck #2:
Enter GOOGLER as a code

Most of these work.