My Favorite Liberal and I both drive Scion xBs. We are often driving to the same place, but will take two cars simply because I usually like to arrive early and she is habitually late. So when we drive our two oh-so-virtuous small cars and park them right next to one another, we are getting a combined 12 MPG (We always drive real fast, because I like to arrive early and she is always late... but you knew that).
But O'Bambi's Petrol Police will wave us right through the roadblock. It is only the SUV drivers that will be pulled aside for re-education.