The unique minicar in Japan is subject to various legal restrictions regarding body size, engine volume and seating capacity, and loading, while it is given privilege with regard to tax and insurance. And today it is not merely an even smaller version of small-size vehicles. It is independently viewed as an economical vehicle for which technical efforts have been undertaken to ensure functional and performance equality to small-size vehicles. And these efforts are successfully in progress resulting in the feature of smallness remaining intact. In other words, the Japanese minicar is in the process of improving high-speed capabilities with general equality being maintained to that of small-size vehicles regarding interior space and urban travel.