Hydrogen or Compressed Natural Gas? Neither!

Why can't I find a gas-hydrogen hybrid? I bet you could get 100 MPG and decent power out of one, yet no one that I know of is making them. There are kits to convert your car, but do those work? I've seen studies showing they do, so why doesn't a manufacturer start puting them in their cars? Why are there incentives to buy CNG cars, yet no filling stations? I would have to drive about 25 miles from my house to fill up. It's not as cost effective as it could be. When will we see more efficient cars that rely something other than gasoline and are cost effective at the same time?