The well-known film is now a feelgood stage musical in Michael Gyngell and Mark Haddigan's adaptation, with Don and his fellow London Transport bus mechanics journeying through Paris, the Alps, Italy and then Greece, along the way picking up three young girls in a clapped-out Morris Minor and a young American pop star on the run from her domineering mother, and all to the strains of a hit-filled score featuring "In the Country", "Summer Holiday", "I Could Easily Fall in Love with You", "Bachelor Boy", "Move It", "Living Doll", "The Young Ones" and "On the Beach".

Four London Transport mechanics are allowed by the firm to take a red double-decker Routemaster bus to France because otherwise they'd have to go to Clacton for their summer holiday; they then pick up three young English women from an obscure French roadside where they've broken down on their way to Athens, by car; a fourth young woman joins the gang by hiding away on the bus while everyone's out at a local bar one evening, after she's run away from her bossy mother who's intent on making her a starlet presumably on the French cabaret circuit.

But in a marvelous strand of Shakespearean transvestitism she disguises herself as a fourteen year old boy for no discernable reason and gets away with it until dancing so vigorously in the Act One finale her hat comes off and everyone sees she's a girl. Then once the numbers are equalized everyone falls in love and all sorts of madcap adventures ensue until they arrive in Athens and the boys receive a telegram from London Transport offering them funding for something or other and people get married to one another and everyone dances into a frenzy until the curtain comes down. None of it makes a dreadful lot of sense.