These cars are not for sale, these are fleet vehicles and are loaned to celebrities and dignitaries. They have plates because they are manufacturer plates. There are only a few places to fuel these up. These will not be produced for the masses until there is an infrastructure to fuel them. BMW just released an all hydrogen model, to join the hydrogen/gas versions.
When they start packaging wind turbines/solar panels in a prepackaged system to create self sufficient refueling stations for hydrogen we will begin to see more hydrogen cars!