Hydrogen has got real problems.....

It's got an energy density roughly four to six times less than petrol; which means you either have very much larger fuel tanks or have a drastically reduced range (which is a tad awkward with near zero infrastructure from which to refill your hydrogen car!)
There's also major issues with how the hydrogen is stored in the vehicle; as a liquid the tank needs constant cooling to -253C (yes that's
minus two hundred and fifty three degrees C!!

) IIRC the BMW hydrogen car, which uses liquid hydrogen, will vent to atmosphere, ie loose, all of it's hydrogen fuel within 10-12 days as the tank naturally heats up or you burn fuel when the car is idle to keep the tank cool

Storing it as a pressurised gas at around 700 bar; ie seven hundred times higher than normal atmospheric pressure, requires some pretty heavy engineering of tanks and if the tank is ruptured it's going to be a whole world of pain.
There's also the issue of how the hydrogen is manufactured; currently it's mainly done with fossil fuels which kind of defeats to object of being a 'green' solution.
IMNSHO, the only positive aspect of hydrogen as a mobile fuel is that the otherwise pretty useless wind turbines could be used to create it whenever there's enough, but not too much

, wind. However, we'd probably need millions more of them to make a hydrogen infrastructure viable.