The latest guide that shows you how to build and install a DIY hydrogen car kit is Half Water Half Gas. I think the main reason why people are deciding to give this technology a go, is that it offers huge potential savings on fuel costs (up to 60%). Even just the huge savings in fuel costs make this technology a winner, not to mention how it could positively affect the environment.Whats different about Half Water Half Gas then? Well its really the same concept that earlier guides like Water4Gas use. Even though pretty much all of the Do-It-Yourself guides are based on the same system, Half Water Half Gas manages to present the information in a new and fresh way and makes it easier to understand some of the trickier stages. The guide includes video as part of the guide format, and this has a huge impact on how one is able to follow the process, it helps many people get unstuck.