In 1929 France overtook England as the second largest manufacturer of cars in the world.
By 1938 car manufacturing was the third largest industry in Britain.
By 1952 cars were the largest British export.
In 1960 British Motor Corporation was the tenth largest company in the world outside the United States, with annual sales of $969 million. Ford Motor of Britain was the 19th largest company outside the US, with annual sales of $753 million.
In 1965 British Ford employed 62,418 people and had capital of £195 million. BMC employed 93,000 people and had capital of £118 million. Leyland Motor had capital of £96 million. Vauxhall Motors had capital of £83 million and employed 33,754 people. Rootes had capital of £46 million.
BMC became British Leyland, and was, by 1970, the largest single exporter in Britain, shipping goods worth £320 million (equivalent to £4.3 billion today). Its marques included Rover, Morris, Mini, MG, Land Rover, Range Rover and Jaguar.
The company was brought to its knees by flawed car designs, poor management and excessive strikes by its workforce. While Rover and Morris had been merged in 1968, the constituent companies continued to act like independent companies, stealing market share from each other and failing to share information and skills.
British Leyland demonstrates the danger of grouping various companies under one management system: what if that management is incompetent? Amalgamation often makes sense (the strength in numbers argument), but mergers can also result in weak companies dragging strong companies down with them.
In 2015, the Nissan plant in Sunderland, North East England, produces more cars annually (500,000) than Italy (400,000). This demonstrates clearly that there is no inherent reason why cars can not be profitably manufactured in Britain.