This is a whole new dimension to the idea of carpooling. If it saves energy to have two people in a single car, it will save even more with more passengers. Some British Ladies took this idea to the max. There were 28 them, I may assume all good friends, because they managed to squeeze inside a Mini.
The Ladies established a new world record which has been validated by Guinness, and everybody will note that a Mini has a much lower fuel consumption than a bus. One question though: why were there only women? Could be more fun with a guy in the middle…