500 miles of range? You could get by making the fuel tank bigger. I assume you meant miles per gallon or something?
of course, this range is only correct with best circumstances, in practice it will be less
Fossil companies are keen on hydrogen as they can still pump their oil.
Edit: according to the specs, it should have a range of 960 km (597 miles) under optimal conditions. It sounds more than I would expect, but then the car is almost 20 years old. Still, the low fuel consumption is one of the reasons I keep it -- it uses less fuel than modern hybrids do.