The story of the series is the aftermath of a serious accident, which is shown at the end of episode one.

The Rover spins after the driver is distracted by the passenger in the unknown car. It is then t-boned by the Ford Ka. The Mercedes Sprinter goes up the back of the Ka, and ends up on it's side on the other carriageway, where it gets hit by the BMW, which is being chased by the Mondeo.

The Mercedes S500 hits the Rover, and the Volvo 850, I think, hits the Ka.