The SAM looks like a load of fun for someone who might otherwise get a motorscooter or would take the bus if only it ran more conveniently. But the reality of the US is that suburbs connected by highways (and with very limited bus service) are very popular places to live, that many people have families and that we tend to grocery shop for the week rather than for the next meal. All of these factors mean that for the majority of people, this type of vehicle would not be a practical primary car. We drive too far, too fast, and carry too much stuff with us.