(Just a little detail - I noticed someone posted a press release about the air car, that's why I wanned to add some quick remark.)
Big advantages of the air car over battery or hydrogen powered vehicles are:
-no need for polluting materials as in the electrolytes of batteries (zinc, lead, nickel etc), reducing one of the world's most dirty forms of waste
-extremely simple and durable
-very fast recharge, compared to batteries (2-3 minutes at a gas station) - pretty much like filling her up with gasoline
-no need for expensive fuel cells (which most often, up till now, require platinum or other expensive materials for their catalysts or electrolyte membranes)
-no need for an entirely new infrastructure (as in hydrogen, or zinc-air batteries)
Compressed air may well be a cheap, simple and viable form of energy for basic transport needs.
Any skeptics of the concept?
(A big disadvantage for some: it was invented by a Frenchie
)