Don't change, sue
I continue to be puzzled by the car industry's ongoing fight against better mileage (Bennington Banner - Headlines.) Imagine how moribund the computer industry would be if processors never got faster. You'd only buy a new computer when your old one got too dusty.
If mileage requirements went up, people wouldn't buy FEWER cars. They'd buy more cars, more often. Yes, there's no question that short-sighted consumers are regularly seduced by low initial prices or big car styling and buy a car that costs them a lot more in the long run. But if mileage standards go up, those cars cease to be an option. What happens instead is that there's movement, always a car a little better as they march to the standard, which gives you a reason to upgrade.
The result would be a race to make better and better cars (and to buy cars that are cheaper and cheaper to operate.) If the cars are cheaper to run, then, over time, people will actually be willing to pay more for them, won't they?
If I were a big company CEO facing such an incredible level of uncertainty about the key input to my product (the price of gas), why wouldn't this be a great way to simultaneously level the playing field (ten years from now, which is plenty of time to get ready).
It's like the cigarette companies. Think about how much they would have pocketed in profits if they had supported a ban on advertising ten years ago. Billions and billions of dollars...
In the face of change, reactionary stuck companies don't look to marketing or innovation. They sue.