Cheat List:
Pause the game and enter a cheat. All codes work on the latest patch (so get one).

Bouncy suspensions/boundaries ... bouncy
Abnormally good traction ... sticky
Abnormally bad traction ... slippery
Double game speed ... turbo
Infinite bottle rockets ... war
Disable collisions ... ghost
CPU drivers get road rage ... hitme
Track hazards missing ... bugoff
Low gravity ... moon
High gravity ... heavy