Yup. BMW made a liquid hydrogen-powered car and the result is...not good. Nothing more than publicity stunt. https://www.youtube.com/watch?v=AouW9_jyZck http

Yup. BMW made a liquid hydrogen-powered car and the result is...not good. Nothing more than publicity stunt. https://www.youtube.com/watch?v=AouW9_jyZck https://www.youtube.com/watch?v=AouW9_jyZck The TL;DW is that since you can't keep it cold enough, eventually the liquid starts to convert to gas, pressure builds up in the tank, and a vent is needed to allow the hydrogen gas to escape. Which then poses a problem, since hydrogen gas is VERY explosive, you can't keep this car in your garage. You have to keep it outside. Then of course there's the issue of this comically large tank taking up the enter back of the car.