For instance, our diving gear plus underwater photo gear has cost approximately as much as a car. It consists of precision machined parts, highly sophisticated electronic devices, it needs maintenance, and so on. Now, I don't wish that everybody goes diving instead of driving a car, this would cause a holocaust for marine ecosystems. But ANY other product or service has the same benefit for economy. Managers and sales persons can manage or sell whatever is there.
Engineers are flexible too.
One of my colleges previously did automobile electronics and now he does telecommunications. Industry makes what people buy. If more money would be spent on other products, research efforts on other sectors could be made instead of the research efforts which are needed to achieve miniature improvements on the motor vehicle. There would be sophisticated products we can only dream of. A mobile service robot which could make household work easier, for instance.