[Viffermike]

Yes, it is a contest. Most of Ford's innovations with the Model T apply not to automobiles or automobile manufacturing only, but manufacturing in general -- and others were working on similar mass-production efficiencies already in other realms. The Model T simply was first to market with many of them.

For me, the Beetle is, by far, the most important. Most sold, by a significant measure. Longest manufacturing run, also by a significant measure. First car designed and built 'for the masses' (as opposed to mass-produced). Most influential, particularly regarding ergonomic, functional, simple design (Seriously: Think about it. There would be no Fiat 500 or MINI without a Beetle ... and there would be a very different Japanese auto industry without it, either.)

And this is the case with most wartime innovations, honestly. We have jet airplanes because of the same era. And nuclear energy. And Jeeps: the forerunner to today's SUV.