Experience has shown that people have to be virtually legislated into the cars they should drive. Other countries do this with horsepower taxes, weight taxes, engine displacement taxes, overall size & width (Japan), fuel consumption and tailpipe CO2 emissions. France has most of the above, except a size tax. Japan has a size and width tax. There is a whole range of minicars that are not sold here because they are so narrow that 2 large Americans would rub shoulders in them.
The US only needs a hefty gas guzzler tax (purchase and annual) and a fuel efficiency or tailpipe emission standard. That, with $5 gas will soon drive down car and engine size.