Grist:

The Efficient Vehicle Leadership Act creates a program that rewards consumers who buy cars and trucks that get better gas mileage than the average overall fuel economy required for its class. Motorists who buy models which exceed that CAFE standard will receive a “fuel performance rebate” (claimed on their tax return or paid instantly by the dealer, whichever the buyer prefers), an amount tied to the fuel savings over and above the relevant CAFE standard. The savings can range from several hundred to several thousand dollars, depending on the vehicle’s fuel economy relative to other models of the same size. Conversely, for inefficient, gas-gulping vehicles, manufacturers will be assessed a fuel performance fee to pay for the program.

Here is the short summary:

Efficient Vehicle Leadership Act of 2009 Summary –

And here is the full legislation:

Efficient Vehicle Leadership Act of 2009 –