Michel and Yves, the two grown-up sons of Bernard and Chantal Moreau (an irascible store manager and his charming absent-minded wife), are raising hell in the region. The former is focused on beautiful cars, the latter has a pronounced soft spot for pretty girls, which he finds and picks up with bewildering ease. Among them, the daughter of one of his dad's competitors, whose advertising car he destroys with a chipper-truck and then follows her home. Then a shop-lifter, caught in the act in his dad's store. For his part, Michel is drawn into an incredible plot, believing to perform a stunt for a film where he runs jewels under the cops' noses on behalf of a mafia gang. He will nevertheless become a professional stuntman under the delighted eyes of the public. After crisscrossing the countryside in a superb 1930's Fiat convertible with his brother, then on a motorbike with a not exactly shy girl biker, Yves is led by one of the store customers into an orgy, which he will finally have to leave to rejoin the family home, just in time to see Michel returning from a mission for the police (the capture of a maniac in a nearby farm). When the two brothers meet, they catch their little sister Annie having sex with her lover in the family car. For their part, the parents, although a little shocked by all this vigorous youth, will finally happily rediscover the joys of physical love.