Interesting Wired article on Hydrogen

I read the article about Hydrogen. I then linked off of that page to an article about 'truckers using hydrogen'. If you have not read it, basically there seems to be a Candian company which produces a box that costs between 4K to 14K, depending upon the size of the vehicle, the box pictured was 12"x12"x24" I think, which using 14amps of electricity from the altenator, produces hydrogen from a tank of distilled water which it carriers. The hydrogen is then injected into the intake manifold to mix with the air, and produces hotter combustion, realizing more power and savings on fossil fuel.

Seems simple enough, I wonder if it would work on a Prius.

I wonder if the increase of power realized is greater than the power required to generate the electricity.