Enter the following passwords for these cheats at the Create Driver screen:
3/4 Gravity: FEATHER
Half Gravity on Tracks: FLOAT
More Gravity on Tracks: RADBRAD
No Collision on Cars: BANZAI
Cars Have Only Wheels: WHEELS
Cars Have Fat Tires: FAT TIRES
Win Season: WTFIN
Invincible in Sim Mode: IMMORTAL
Race Two Laps in Season Mode: GEK
Sunset Tracks: SUNNYSKY
Night Tracks: NIGHTRID
Space Tracks: SPACERID