Press Esc and type one of the following codes, then press Esc again:
God mode for current vehicle: CUDDLE
God mode for all friendly vehicles: HUGS
Full ammo: CARESS
Mission skip: IMLAME
Destroy currently targeted vehicle: KISS
Destroy all opponents on radar: LOVE
Freeze CPU vehicles: SYRUP
Freeze time for CPU: MRFREEZE
Self-destruction: NUKEME