What's happening?

Clever, huh? The car isn't going backwards, the car is slowing down, so the system reverses the flow of electricity, sending the leftover power from the wheels back to the battery as it slows down.

Sean, what are hybrid cars?

Hybrid cars have both a petrol engine and an electric motor working together.It can run on electricity at low speed, and when we go faster, the petrol engine kicks in to help out the motor.