Hydrogen Modifications For Cars?

I have recently seen these modifications for your car to make it run on water or water along with gasoline. Does anyone know if this is actually a feasible solution, it seems a bit too good to be true, or maybe a wave of the future that GM is paying billions of dollars to hush up? I added a few links below claiming these products, I found these links on some tech forums that claim they work and was wondering if anyone had a second opinion. Thanks.

http://yakeums.water4gas.hop.clickbank.n... (http://yakeums.water4gas.hop.clickbank.net/)
Claims to combine water and gas to double mileage...

http://yakeums.centemax.hop.clickbank.ne... (http://yakeums.centemax.hop.clickbank.net/)
Claims to run your car completely on water

http://yakeums.marketss12.hop.clickbank.... (http://yakeums.marketss12.hop.clickbank.net/)
Half water Half Gas

I dunno about that, the sites seem a little bush league if you ask me... but it may be worth it just to try since the prices are so low for such a claim. Anyone have any info?

I have read the books of the original inventors & seller of this technology (ie. oxyhydrogen or Brown's gas hybrid assist & better hydrocarbon combustion). This does seem scientifically feasible, although I have not modified my car for it as yet. Apparently 1000s have & are saving $100s-1000s annually in gas$. More notably commercial ventures are also saving$ through this technology. The latest I have heard is that USA police are using the technology, which says something for its authenticity & legality. This also confirms the literature that this technology not only enhances fuel economy, but also engine performance. This is a real $ spinner for any business with a high dependence on fuel, reputedly trucks are saving 25% on fuel by using this technology, so that it is much more than just an ethical technology (ie. less CO2 but u pay 4 it), it is an economic solution to a high fuel$. This is partiacularly the case for diy modification & replication which is possible with this technology. Discovering forgotten technology sometimes pays handsomely. Cheers.