A Kill Switch is REQUIRED.

I believe it is considered safety equipment, and therefore exempt from the budget.

The Kill Switch should be easily recognizable as such, so that a Track Marshal or any racer can easily disable a runaway car.

Some cars have multiple Kill Switches.

Some cars also have a Dead Man Switch. Typically this is a small rope that goes around a drivers wrist with a wire loop and an Anderson connector. If the driver becomes separated from the vehicle (or yanks their arm too far from the steering device) the connector disconnects killing power to the car.