The vehicles got bigger in the new millennium, as you indicated. What happened? 9/11 happened. After 9/11, Americans were PISSED. We bought Toby Keith music like crazy. We voted for Dubya a second time. And, yes, we wanted bigger and bigger cars and trucks. It was venting and showing off our collective machismo, and it continues to this day, especially among conservatives. It reminds the world that Americans are relevant and have big dicks. I don't think safety has too much to do with it. It's a way of feeling strong and relevant in an increasingly complicated world.