Why not give tax incentives to help future car development? People who buy future cars with clean energy technology can get tax credits so they pay less. That will cause people to think much more seriously about buying green automobiles.

In addition, companies which develop future cars could also receive tax breaks, especially on research and development costs.

The government could also buy only green future cars. Just providing the police, army and other wings of government would be a substantial push for future cars. Let all of the American politicians use future cars. That would make a really strong statement.