One bonus with hydrogen fuel cars if they can find a way to produce it cheaply, is reduced mining of materials, Which not only causes pollution as a bi product of mining these materials but also the use of heavy machinery. Also the deeper they dig for these materials, the waste materials are burying towns etc etc.
Another massive bonus of hydrogen fuel cells cars is they still go brum brum brum peep peep which not only keeps the petrol heads happy but also the makers of sports cars as seen on op gear Sunday as @Elliot also pointed out.
Another massive win is a conventional engine can be adapted to run on hydrogen fairly easily.