The Audi engineers have transformed the rear of the car into a large, continuous illuminated surface, with countless small points of light flickering like a swarm of of bees or a shoal of fish. The red dots follow the movements of the vehicle. The faster the car is driven, the faster the dots move; they flow to the right, when a right turn is made; when the car is braked, they flow forwards, so that the following driver can see what the driver of the car in front is doing.