Franz argues automotive tinkering was a form of popular culture, enabling drivers and owners to be active rather than passive consumers in changing the technology to suit their needs, primarily for auto touring. The Ford Motor Company archived numerous letters from such inventors suggesting and by the 1920s, automobile manufacturers were capitalizing on consumer innovations. They adopted accessories, including the ‘trunk,’ which was initially attached to the outside of the car by straps, by incorporating them into the standard design of the American automobile. But ultimately these consumer-driven efforts tapered out. Earl Tupper, the later inventor of the Tupperware, patented a top for rumble seats in the 1930s, but could not commercialize it because of the growing popularity of enclosed cars.

The growth of such streamlined designs made the car more difficult to modify. The auto shows and world’s fair exhibits of that era popularized the idea that corporate scientists at Ford and General Motors and engineers, not drivers, were in charge of technological innovation in the auto industry. A burgeoning industry of scientists and magazines like Automobile Girls relegated women, who originally comprised a substantial portion of tinkerers in the 1910s and 1920s (as Virginia Scarf argued in Taking the Wheel (1991), to the domestic jobs of cooking and cleaning while on long-distance travels.