Acton formed an urban district and, later, municipal borough of Middlesex from 1894 to 1965. Its former area was used to form part of the London Borough of Ealing in 1965. During the 20th century Acton was a major industrial centre employing tens of thousands of people, particularly in the motor vehicles and components industries. The industries of North Acton merged with the great industrial concentrations of Park Royal and Harlesden. One of the most important firms was Renault of France, which made cars, including the 4CV and the Renault Dauphine, at a factory in North Acton from 1926 until 1960. Renault has remained on the site continuously since the 1920s and still has its main London showroom on the Park Royal site.