CNN: Hydrogen and electric vehicles might be leading the charge, so to speak, towards cleaner transport, but will cars powered by air and the sun ever surpass the sales figures of gasoline cars? MDI boss Guy Negre with his AirPods which start a six-month trial at two European airports in 2009. It might seem ridiculous, but air — yes, air — can power a car. Compressed air, stored in a carbon-fiber tank and then released, expands to drive the engine’s pistons in the same way …