We need to look for alternate fuel sources to reduce our dependence on oil. However, water is not a fuel source, and every moment you spend pursuing it is a moment less you have to work toward something legitimate.
"The vehicle that Genepax demonstrated to the press in 2008 was a REVAi electric car, manufactured in India and sold in the UK as the G-Wiz."
The car in that video is an electric, and wasn't even running on water.
Take a look at the rest of the stories on that Wikipedia page. Just one fraud after another. That's your water-fuelled car legacy.