Perhaps a better policy would be to ban the sale of all 6 cylinder (and above) cars. The only organization, that would be allowed to have high powered cars, would be the police force. This policy would have a two fold effect - ie less carbon emissions (less fuel being used), and less auto theft, and less high speed chases, and lives being saved.
The reality, is that mostly, cars are only used by one person. One of those three wheeled Messerschmitt's is probably, what most people need