Enter the following driver names when creating or editing a driver in Build Mode: 

FLYSKYHGH   Rocket car
FLYBOY      Fly non-stop   
FSTFRWRD    Fast mode   
LNFRRRM     Mirrored Rocket Racer Run    
MXPMX       Max power-ups  
NCHSSS      Chassis is invisible   
NDRVR       Driver is invisible   
NMRCHTS     Disable cheats
NSLWJ       Won't slow down  
NWHLS       No wheels  
PGLLGRN     Turbo power-ups only   
PGLLRD      Shooter attacking power-ups only 
PGLLYLL     Mine power-ups only   
RPCRNLY     Grapple power-ups only
TurboFreak  Beat the whole game