I think overall, it's a bad idea.
It costs way more to get hydrogen TO your engine, start to finish, than you get from it.
It is difficult to store, as you are finding out.
It CANNOT be extracted from water fast enough in the storage space that a vehicle has to offer, unless you have it set up in a 40 foot semi trailer behind your car.
Can you imagine the damage it would do to our water supply if everyone started sucking water out of the ground to power their vehicles? We'd have "gas" but would die of thirst.
All this "green" crap makes me ill. Just like corn ethanol, nice idea but millions would starve to death just so we can be kind to Al Gore the idiot and jump on the 3 wheeled band wagon.
Natural gas is a win/win situation. Can be burned in it's natural state, billions of cubic feet of it ready to go, cars are somewhat easily converted and if you have gas heat or cooking at your house, all you need is a transfer station, however pricey they still are.