As the result of an impulsive wager two friendly rivals engage in a race on their return journey from the London to Brighton veteran car rally. Every year, barrister Alan McKim (John Gregson) and wife Wendy (Dinah Sheridan) compete against Alan's friend (and Wendy's former beau), Ambrose Claverhouse (Kenneth More), in the London to Brighton vintage car race. This time round, however, Alan's 1904 roadster, 'Genevieve', breaks down on route. Angered by Ambrose's jokes at the expense of his beloved car, Alan bets his rival that he can beat him on the return journey to London - and the race is on! Larry Adler's harmonica score was nominated for an Oscar. Also included is a 'making of' documentary.