My sister is looking to buy a new car and will be commuting over an hour each way to her new (and awesome) job. She's looking for something that has great highway gas mileage. I'm sure many of you commute, so i thought i'd just throw the question out there. She's not really decided on anything yet, but wants to start with the best gas mileage cars.. She was thinking about the Prius, but i've heard that they're better for "city" driving, not "highway"... hmmm? TIA!