By Cat DiStasio
Green transportation is advancing by leaps and bounds. In just the past few months, we've seen a solar-powered airplane complete historic flights, self-driving vehicles hit the streets and cars make astounding achievements in fuel efficiency. However, for every big breakthrough there are scores of off-the-wall designs that are almost too out there to believe. Read on for seven of the weirdest, wackiest and most wonderfully creative green vehicles around.