Alcide Darbois, a small-time garage owner, and his sister Ursule come into a fabulous inheritance and become powerful industrialists. The cars they make a re very successful on the French market. Now a bit of a snob, Alcide decides to marry his daughter Suzanne to Marquis Gaëtan de la Michodière, but the young lady is actually in love with Bégonia, her father's chief worker. A car racing event will resolve the situation.