An answer is in the linked article: > That first taste of triumph only whetted the appetite. By the 1930s, with another war effort in the works, dealers went s

An answer is in the linked article: > That first taste of triumph only whetted the appetite. By the 1930s, with another war effort in the works, dealers went state by state. “At that time, there was lots of attention being paid to small business as having inherent virtue and the need to protect mom-and-pop shops,” Daniel Crane, a professor at the University of Michigan Law School, told me. “They embraced that story, and were extremely successful at getting legislatures in all 50 states to strictly regulate how cars were sold.” In 17 states, it is outright illegal for car manufacturers to sell cars at all.