i don't know of a code to get you to the other tracks on that game, but here's what i lifted from
www.cheatcc.com for ya. kinda goofy, but if ya get bored.....
Greater acceleration and maximum speed
Choose the "Extra" option at the main menu, then choose the "Codes" selection. Enter "EVOPOWER" as a code.
High pitched commentary
Choose the "Extra" option at the main menu, then choose the "Codes" selection. Enter "HELIUMAID" as a code.
Cars with no chassis
Choose the "Extra" option at the main menu, then choose the "Codes" selection. Enter "THATSSTUPID" as a code.
Flying cars in replays
Choose the "Extra" option at the main menu, then choose the "Codes" selection. Enter "FLOATYLIGHT" as a code.
Overhead camera
Choose the "Extra" option at the main menu, then choose the "Codes" selection. Enter "DOWNBELOW" as a code.
Reversed camera
Choose the "Extra" option at the main menu, then choose the "Codes" selection. Enter "ONTHECEILING" as a code.
Underwater graphics
Choose the "Extra" option at the main menu, then choose the "Codes" selection. Enter "WIBBLYWOBBLY" as a code.
Psychedelic graphics
Choose the "Extra" option at the main menu, then choose the "Codes" selection. Enter "IMGOINGCRAZY" as a code.