Racing fans are sure to enjoy a history that takes in Patrick Head's innovative car designs in the late 1970s and the 1986 rivalry between Nigel Mansell and Nelson Piquet.

The film is let down by an overlong running time and a prurient attempt to crowbar an emotional response from the taciturn Williams.

Frank Williams has his legacy well and truly besmirched in this highly unflattering and very juicy portrait.

What emerges is a fascinating and deeply personal family history, though die-hard petrol-heads may wish for a little more focus on the racetrack.