A Donut is a stunt maneuver that doesn't count towards any game mode but can still be performed. It is most commonly seen after entering an offline Stunt Run event.
A Donut can be performed by aggressively applying acceleration with turning from a stationary or slow moving position. Some vehicles such as the Kitano Hydros Custom are front wheel drive and can only perform a Donut in reverse.
Bikes can do donuts while performing a Wheelie.