re: Who buys the commuter car?
California has passed a law that mandates low automobile CO2 emissions. The only way to do this in any form of internal combustion engine is to reduce the engine size.
What about improving efficiency? Electronic fuel injection, variable valve timing, contolled ignition, modified cylinder head and piston design, better automatic transmissions (where used), etc, etc, can all provide better fuel economy with no loss (or even a gain) in power - better fuel economy means less CO2 emissions.
Lower weight also improves fuel economy and reduces CO2.