As CAFE works on the number of cars sold, clearly all a manufacturer has to do is to introduce a very VERY cheap high mpg rated car to offset the current consumption.
So .... look forward to a Tata Nano being sold for $1 with every SUV in the coming years.
CAFE doesn't say the owner has to DRIVE the better fuel consumption only BUY it.
I fully expect the big US manufacturers to exploit that kind of loophole the same way they did with the SUV market