During an economic boom, companies that made transportation vehicles would concentrate on maximizing production to meet the high demand for new vehicles. They would not want to introduce radical changes that would require an extensive retooling of their factory. There is one big exception to this rule. Henry Ford shut down the production of all of his factories for eight months in 1927. His Model T, which was introduced in 1908, was still a very popular model in the 1920 to 1923 period. Ford had a fifty percent share of the US auto market between 1920 and 1923, but starting in 1924, GM began to cut deeply into Ford's market share with more modern and better looking cars. Walter Chrysler introduced his eponymous car brand in 1924. It was considered to be America's first modern car. It had an enclosed body, electric head lights, four wheel hydraulic brakes and used an ignition key to activate the self starter. The 1924 Chrysler took all of the early innovations that moved a car from an open top horseless carriage and put them all on one, all weather car. General Motors soon followed this lead and they both left the Ford Model T in the dust. Sales of the Model T dropped from 1.8 million in the 1923 model year to "only" 480,000 in the 1927 model year. Ford and his engineers designed the Model A, which was a low cost, four cylinder car that was just as modern as the other cars being built by rival automobile companies. The Model A was also the first low cost car to have shock absorbers. It remained in production for just four years. In 1932, Ford kept the basic Model A frame and body, but upgraded the motor to a small block V-8. That helped to jump start Ford's sales in the middle of the Great Depression. Prior to 1932, the V-8 engine was only used in expensive luxury cars.
Auto companies were willing to innovate during hard economic times. Since their tried and true products were not selling, a dynamic new model might spark sales. Sometimes this worked, but sometimes it led to a big flop. The 1934 Chrysler Air Flow was a good example of a car that was too radical and futuristic to garner much in the way of sales.
Sources. "Chrysler: The life and times of an automotive genius" by Vincent Curcio. "Wheels for the World: Henry Ford, His Company and a Century of Progress" by Douglas Brinkley.