About the "Water Fueled Car" (sorry to dredge up this old post, but I just stumbled across it). I have some first-hand experience that I thought I'd share.
I was a junior in high school when this hit the news. Our high school science club tried to duplicate Mr. Meyer's claims, with the help of our chemistry teachers and some chemical engineers that worked with my Dad. Meyer was tight-lipped about his process, but it appeared to be nothing more than traditional water electrolysis spurred on by a catalyst (HHO, a.k.a. Oxyhydrogen, or as Meyer called it "Brown's Gas"). Meyer also claimed his system could produce burnable hydrogen fast enough and in enough quantities to power a dune buggy as it was driven at highway speeds, and that he replaced a conventional engine's spark plugs with injectors that introduced the hydrogen into the engine's cylinders. BTW, Meyer did not "mysteriously die" soon after going public with his invention in 1976 - he died in 1998 of a cerebral aneurysm. I don't know if he was threatened by oil company executives as he claimed, but he was convicted of fraud in 1996 and was being sued by investors.
Looking at what Meyer published at the time, and also looking at his patents (which became public domain in 1996) there is not enough information for anybody to build or duplicate what Meyer claimed he built and did. We could never find where Meyer actually demonstrated his dune buggy in operation (the one he claimed could travel from LA to NYC on 22 gallons of water). His claims often didn't make sense to people who knew much about internal combustion engines. For example, without a spark plug how can he ignite the hydrogen? Hydrogen makes a poor diesel fuel, if he tried to ignite it via compression.
Regardless, we decided to try to convert a lawnmower engine to run on hydrogen. We did get it to work (sort of) but we ran into a host of problems:
1. It takes a lot of hydrogen - hydrogen has only about 45% of the energy density of gasoline.
2. Due to its low energy density, to carry enough hydrogen to get practical driving range you need to compress it. Compressing it wastes energy, and you need a tank that is much larger than a gas tank. Tanks that hold compressed gases require certification, and need to be recertified or replaced every five years.
3. Electrolysis is a slow process, and takes a lot of energy (more energy than the energy value of the hydrogen you get). We found that the amount of hydrogen we could create using standard high school chemistry lab equipment over a twelve hour period was only enough to make our engine start and sputter for a few minutes. Granted we did not try a catalyst (the HHO was unobtainable) and our engine kept its spark plug while substituting a fuel injector for its carburetor, so our setup was different than Meyer's.
4. You need pure water. Any contaminants mess with the electrolysis process and also contaminate the hydrogen produced. Our adult chemists felt that even contaminants in the air would hinder the process. It would be difficult to refuel the engine (pour in new water) without contaminating it in some way.
5. It is hard to store and transmit hydrogen. Being a very small molecule it leaks very easily. It is also corrosive.
Years later I met a guy who had bought and tried a conversion kit that was supposed to make your car run on water. It turned out to be a simple electrolysis system, with an output tube that fed the hydrogen into the car's air cleaner. After finding that the original kit achieved almost nothing, he modified it to where he could run electrolysis overnight and store the hydrogen - that produced enough hydrogen to start his engine and drive the car for about a couple blocks. Despite its claims, there was no way that the kit could produce enough hydrogen quickly enough to power a road-going car. He tried to expand the system further, but ended up with a small explosion that ruined his carburetor.
Today most hydrogen is produced by natural gas reforming. That is an expensive process - the hydrogen produced costs two to three times what gasoline costs (in order to do the same amount of work). Not saying that hydrogen is a dead end - just saying that with our current technology it is not competitive.