The cars and trucks that have gone into production are Hydrogen gas into ICE engines, using capsules to hold the gas. They are not fuel cell.
However in terms of fuel cell vehicles, I was involved in the Bus Industry in 2005/6, evaluating future product so looking closely at the Perth PTA trial with Mercedes Benz fuel cell buses. To give Mercedes Benz credit due they spent a lot of money setting up the buses and at the end of the trial the passengers liked the lower floors and the quiet operation, but at that time the Prime Cost of the chassis was three times the cost of a diesel.
I ruled it out on Prime Cost, without the in-service Fuel Cell vs Diesel Maintenance component, and happen to have 2004 figures here to show the impact, using costing done for another MTT company.
Bus Chassis: Mercedes Benz 0405NH/0500 $198,934.00
Body: $225,500.00
Total: $424,434.00
Bus Chassis: Mercedes Benz Fuel Cell $596,802.00
Body: $225,500.00
Total: $822,306.00
Fuel Cell Premium $397,872.00
Premium x 600 normal Tender Lot $238,723,200.00
Even at State Government level purchasing it was clear that $238.7 million up front premium was going to be too big to swallow.
About the same time Honda built a fuel cell Civic and sent them to the US where they were offered to customers on a 12 months lease. One of them came to Australia for evaluation, but it all died away. There are still companies trialling them and maybe one day they'll get the magic balance where you put water in the tank, the fuel cell breaks out the H from the 02, and the engine supplies the electricity needed to power the fuel cell.