As of 2014, there are several prototype wind-powered cars in existence, including models capable of travelling over 100 mph. However, mass-produced commercial wind-powered cars based on the existing models are unlikely to replace combustion engine vehicles, because wind-powered cars can only travel when there is enough wind to power them.
All existing wind-powered car prototypes have similar designs. They have three wheels and sit low to the ground to reduce air resistance, and they have a large turbine mounted on the back to harness the wind. This turbine functions similarly to a windmill. Since the turbine converts wind into energy, the cars do not have to be facing downwind in order to work.