Do you think you lives would improve for the better or for the worse?
I don't know. If you think YOU would have a better life if YOU had a car powered by fuel cells then get one. Meanwhile, cars aren't powered by fuel cells any more than cars are powered by gas tanks. It's the gas IN the tank that makes the car go. Where does the fuel come from that fuels your fuel cells?
Well if you could magically snap your fingers and have all cars powered by fuels cells I think you will find no difference in your life at all. Also remember that fuel cell cars will be pumping the most powerful green house into the air. Water vapor. So we will still have annoying environmentalists claiming that we are destroying the universe. So everything will be the same.