This program is so wrong in so many ways. It is a typical liberal "feel good" program that cannot accomplish anything it proposes.
It will cannabilize future sales of autos by artificaially accelerating them to the present, thus exacerbating the auto industries problems, years out.
With the US government now owners of GM and Chrysler, this has conflict of interest all over it.
So sad.

Human nature: Increasing the fleet's gas mileage will not decrease dependence on foreign oil, it will only increase the amount of miles driven, overall fuel consumption flat to higher, consuming other resources like tires, oil, and roads.
Simply look at the last 20 years. The fleets average MPG is way up, but even factoring out the increase in # of vehicles, fuel consumption is not down.
I don't have backup for this, other than my own research over time. So take it or leave it. Its my opinion.
PS: Another point I just heard from a financial site is that this program rewards people who have made bad decisions. That is a hallmark of the whole recovery effort. The bankers and brokers who screwed everything, the borrowers who went in over their heads, the auto manufacturers who didn't plan for the future, are all being rewarded (bailed out) for their bad decisions and those who made good decisions are left to their own devices. This is bad policy.
The incompetent must be allowed to fail and the competent will bubble up to take their place. But so far the courage to let this happen is not there.
Or so i think.