Enter the following codes at the Password menu

Result - Password

70S Springs-VANISHING
All Cars-FLEETING
All Tracks (PAL Version Only)-MAGIC23
Chrome Cars-T2
Double Height-TWINPEAKS
Exploding Kerbs-KERBKRAWL
Extra Power-GRUNTSOME
Invincible Car-MADCAB
Low Gravity-EUROPA
Mirror Mode-WEFLIPPED
Motion Blur-ETHANOL
Nitro Button-GLYCERINE
Slot Cars-RAILROAD
Tough Spot Cars-REARFEAR