Devils advocate, fuel cell cars - flatfour
When we eventually all drive around with a fuel cell, what are the risks of explosion? Hydrogen is I remember from a botched chemistry experiment very very explosive.

When all is working ok and all we have is a trickle of water out the exhaust, what will be the effects on an icy road.

If we don't don't have a water cooling system, how are we going to get the heater to work in winter, may be the old petrol burner they fitted to the air cooled VW variants.