I drive a Chrysler PT Cruiser, which gets a piddly 20mpg. I'd love to get a Toyota Yaris or some similar model that gets ~40mpg, but between college and gas money, it's probably going to be a bit of time before I can invest in an efficient car. Remember, much of the youth of America either get
A. A used deathtrap because that's all they can afford, or
B. What their parents get them.
Even when they buy their first "real" car, it may not be a golden paragon of fuel efficiency, because cheap is still the issue. But kudos to Toyota for making the Yaris fuel efficient and reasonably priced.
Fuel efficiency will definitely fly with he youth of America when somebody releases a $5000 car that trims all the fat from most cars and just leaves it with a green engine.