Two men at an antique car rally with a wife and a date decide to race back to London and have difficulties.
Wendy McKim (Dinah Sheridan) brings home groceries and prepares dinner for her husband Alan McKim (John Gregson). Ambrose Claverhouse (Kenneth More) arrives and invites them to a party after the antique car run. Wendy does not want to go and quarrels with Alan. She puts on a special hat, and they make up.
Alan and Wendy meet Rosalind Peters (Kay Kendall), who is going in Ambrose’s car with her dog. They leave London in open cars. Alan’s car stops, and Wendy spills coffee. She changes clothes behind a bush. Alan asks if she wants to go back; she says no, and they argue. His car stops again, and Wendy shows him the food she brought. They eat. Ambrose and Rosalind pass them and then break down. Alan goes by and laughs. His car goes haywire and says Ambrose has what he needs, but Ambrose drives by.
Ambrose and Rosalind arrive in Brighton in time, but Alan and Wendy are late. They get a room on the fifth floor without a lift. The four meet at dinner. Ambrose dances with Wendy, and Rosalind suggests that Ambrose should be jealous. Rosalind plays the trumpet well and passes out. Wendy giggles. Alan asks her about Ambrose and her on the ’49 run. Wendy asks Alan to make love to her, and he walks out.
Ambrose finds Alan with his car, and they talk about Wendy. They decide to race back to London and bet £100. Alan works on his car all night. Wendy does not like the bet, and Alan sleeps.
Ambrose lets Alan get a head start. Ambrose can’t start his car and gets people to push. Alan is stopped by two policemen for speeding, but Wendy persuades them not to give a ticket. Ambrose is stuck in water and has Rosalind push. Alan has his car towed, and Wendy says it is unfair. The four talk, and Alan can’t get his car started.
Ambrose and Rosalind stop and lay down. Ambrose shows the part he took to stop Alan, who has it replaced. Alan makes a phone call, and Ambrose is told that they had an accident. Ambrose goes back and sees Alan going the other way. Police tell Alan that his car was reported stolen, but he blames Ambrose. They let him go and stop Ambrose.
Wendy tells Alan she needs a stop. Ambrose stops and quarrels with Alan. Police stop the fight and warn them. Ambrose calls off the bet, and Alan agrees. Then Alan bets his car, and they race in the city. Ambrose passes them but is trapped by two cars. Ambrose catches up. An old man admires Alan’s car, and Alan is left behind. Wendy cries and makes Alan promise to pay money instead. They pass Ambrose but get a flat tire. Both cars stop, but Alan wins.
This British comedy is entertaining and amusing if one does not expect too much. Something about cars seems to change people’s personalities when they are driving them.