It's like this: I want to be able to buy cars with great performance at some kind of reasonable price. That means the cost of achieving fuel efficiency should be within a limit where that cost can be recovered against US fuel prices. I don't think it is fair to be paying more because of some kind of intangible benefit related to C02 reduction.
Right now that is possible, but with the coming Obama insane efficiency standards it won't be. It is particularly hard on those of us who like small powerful cars because the rules are set up to allow rednecks to buy big pickups while we get to take up the slack. That is why the Camaro is so damn big.