It's hard to get these cars down to that weight and still include all this mandated safety equipment. IIRC, MPG ratings hit their peaks in the late 80's once 4-bangers started becoming the norm in lighter cars. But it was the added weight of all these luxuries and safety features along with HP wars that brought them down. Correct me if I'm wrong, I probably am but remember hearing this more than once.
If this is to be a possibility I'd have to imagine at least one to two cars out of the entire lineup of every car company being made of aluminum. and then getting enough people to buy the car for it to count will be a whole new issue.
I know in my teg I get an average of 28MPG. Theres just no way I can foresee, with these new standards of testing, anything bigger than a 2.5L V6 even breaking even. Forget about AWD or these RWD cars, their weight is so up there just from an engineering standpoint that it'd be damn near impossible.
Next thing you know they are going to be shoving that pedestrian crap down our throats. These people in the senate, they don't know jack shit about car design or what goes into MPG values, 35 is ludicrous.