I like this ericson engine -if it is real. That sort of efficiency would be a good match to a hybrid vehicle, which is what the descibed air-car strongly resembles. I too doubt the energy storage efficiency of compressed air, the stated 10-20% number seems to be in the right ball park. Of course if this "ericson engine" is real and practical it could be used to charge the batteries of an electric hybrid. This would likely be more costly, but would give outstanding fuel economy.

I'm pretty suspicious of this whole venture however. I could make arguments like if it is such a good idea, how has it been around so long without a product? That line about "advanced magneto-caloric quantum effect" strikes me as pure garbage (I have a degree in astrophysics) -if they actually made that statement, I would consider this to be almost certainly an investment fraud.

Yes they did use the phrase advanced magneto-caloric quantum effect. Look in the last paragraph of http://www.itmdi-energy.com/information/solutions.html