The Carbon Tax
Bjorn Lomborg was the guy the Republicans in Congress used to counter Al Gore's presentation there. Bjorn thinks a carbon tax is a good thing, somewhere between 2 and 14 dollars per ton.
Cars emit about 200 grams of carbon per kilometer. A megagram is about a ton, so you'd emit about a ton every 5000 kilometers, which is about 3000 miles.
So the personal carbon tax for automobiles would be 2-14 dollars per 3000 miles. Given 145,000 mile life expectancy for a car, that'd be $300-$2100 for the life of a car. That last number sounds like a lot. Lots more revenue, of course, would be generated from industry.
Works for me!