The Swedish Wind Wagon Project - www.windwagonproject.se
This art car was entirely made with material used for building traditional sailboats. It was also fully functionnal and able to travel under only wind power, but due to Burning Man regulations, it had to be towed bu a truck. Wind-powered vehicles are not allowed at Burning Man, except windsurfs.
Photo taken at the Burning Man 2012 festival (Black Rock Desert, Nevada).