Clip from the BBC Four documentary "How to Go Faster and Influence People: The Gordon Murray F1 Story" featuring Murrays Design for the Brabham BT46B Fan Car. The full documentary is here:
   • Video  

Some more clips from older documentarties are here:
   • The Brabham BT 46 b Fan Car F1 1978  

From the original BBC description:
"It's 1978 and the world of F1 is gathered at Anderstorp for the Swedish Grand Prix. Bernie Ecclestone's Brabham team is causing a commotion in the pit lane with its new car.
Brabham's brilliant young designer Gordon Murray has stuck an eighteen inch diameter fan on the back of the car -- ostensibly to cool the engine, but with the crucial side effect of sucking the car to the road.
As Murray recalls; 'The Fan Car went round hairpin bends as fast as 150 mph bends. It had a massive advantage.' Brabham's rivals, from Colin Chapman and Mario Andretti to Niki Lauda and Ronnie Peterson, are outraged -- but the Fan Car races on."
Source: http://www.bbc.co.uk/programmes/b01f11hp