"What you gave was a contrived example at best, and not very realistic in the real world."

Agreed, to an extent*. It was simply an attempt to point out the error in the generalization. A Prius driver isn't inherently more "green" than a Navigator driver. I do, in fact, have several friends that have purchased cars for the good gas mileage just BECAUSE they feel it enables them to drive more.

*The SUV example came strait from the real world