Actually, the "Roaring Twenties" did not materialize until after the dawn of the new decade. We came out of World War I trying to regroup from victory in a war that divided the USA. Yet, the 1920s would end on a down note. You probably heard of the Stock Market Crash and the subsequent Great Depression.
There was a time when the future of the automobile was exhibited to the public as a "concept." A concept vehicle was truly a vision of the future for which a few components would be present in new models within a few years later. Others were just straight out of science fiction with none of the concept's ideas brought to market at all.