They tried on mythbusters, when they were doing car myths.
They tried a internet designed electrolysis device, it failed.
But, the car did run on pure hydrogen from and tank.
It worked until it started to catch fire.
A fuel cell is just a fancy battery. Hydrogen is used to charge this battery, not tap water. Hydrogen needs to come from Fossil fuels or is removed from water using electricity.
Therefore, the car would run on electricity (just like a current battery operated remote control car), not water.
People who think Fuel Cell vehicles "run on water" are idiots.
I have very high hopes for the new Honda. Not sure who will win that race, Honda or GM, buy stock in both.
Most hydrogen cars on the road today use "dirty hydrogen" meaning that at some point water was cracked at super high temperatures by another fuel source. There are companies that are creating home fueling stations that use rain water and solar power to generate and store hydrogen. What an awesome day it will be when we can do that everywhere
The sad part is that dirty hydrogen vehicles really only get 85% of the mileage that a gasoline vehicle would get. They eat 15% of the fuel just from the cracking/steam process. That hydrogen Hummer isn't so pretty now is it?
What would they do about road tax if you really never need to run the thing on gas? Could they get you for tax evasion? In Kentucky, they have a tax form if you run home grown fuels in street vehicles. What if you never even burn fuels at all? I guess they would also have to crack down on all the hybrid owners out there too?