Using this Trainer:

Launch the trainer first, then launch the Game and then Press F1 at the Main Menu.

Listen for "Activated".

Press desired option key

Options in Promo:

Numpad 6: End Timed Race

Options:

Numpad 1: Super Acceleration

Numpad 2: Super Brakes

Numpad 3: Super Jump

Numpad 4: Freeze AI Vehicles

Numpad 5: AI Spinout

Numpad 6: End Timed Race

Numpad 7: Super Checkpoint Time

Numpad 8: Style Points Multiplier

Notes:

Numpad 1: Super Acceleration - while racing, press this key to accelerate!

Numpad 2: Super Brakes - while racing, press this key to instantly brake.

Numpad 3: Super Jump - while racing, hold key down to fly upward.

Numpad 4: Freeze AI Vehicles - while racing, toggle this on and the AI vehicles are stuck.

Numpad 5: AI Spinout - while racing press this and the AI spin out.

Numpad 6: End Timed Race - some races you have to last the entire time on the timer.  Press this to end the race.  Toggle back off when not needed.

Numpad 7: Super Checkpoint Time - some races you have to get to the next checkpoint by a certain time.  Toggle this on before the race and the checkpoint timer is huge.

Numpad 8: Style Points Multiplier - most races you earn style points. Toggle this on and you earn them much more quickly.