Hydrogen cars are also still very expensive. At one stage Arnie was driving a hydrogen powered Hummer around California.. the car cost $1 million. As Bluecollar says, the hydrogen manufacturing process is also very inefficient. Also, hydrogen is very dangerous to handle.. how do you spell "Hindenberg"? Electric cars can be implimented now and arent as expensive. Electric vehicles are the way to go.
IMO, the endorsement of hydrogen fueled cars is just another way of delaying any significant change. We'll stick with petrol because electric cars are to expensive to manufacture and batteries are expensive and inefficient. Now when that is not true anymore, those who stand to lose out say that we shouldn't swap to electric because actually hydrogen is the better choice. But its too expensive right now, so stick with gasoline while we try and work out the efficiencies around manufacturing hydrogen fuel and cars become cheaper. When that happens, there will be something else they can then use to delay implementation.