Porsche is a low volume automaker in America so they are exempt from CAFE standards. They also only sell high margin vehicles so they can take the high labor costs.
The issue is not GM being unable to build the best cars in the world (compare Corvette ZR-1 to a 911 GT2), it's the lousy way they approach CAFE standards (Aveo, Cobalt). Can Porsche design and market a car that goes 35 mpg?
But Porsche is not excempt from rigid european / german union standards. And I could have picked Audi or BMW as well and they are not low-volume by any measure.
The issue is not GM being unable to build the best cars in the world (compare Corvette ZR-1 to a 911 GT2), it's the lousy way they approach CAFE standards (Aveo, Cobalt). Can Porsche design and market a car that goes 35 mpg?