Same question from me also. Also, hydrogen is highly explosive, so how can that be safely used in cars without detonating a la Hindenburg whenever there's a collision?
A study on CNG in busses says: "One can therefore conclude that CNG buses are more prone to fire fatality risk by 2.5 times that of diesel buses, with the bus passengers being more at risk by over two orders of magnitude."
source: https://pubmed.ncbi.nlm.nih.gov/15876211/#:~:text=One%20can%....
These are not compelling numbers. Ideally you'd want something safer, not a few times more dangerous.
As I understand, If you make a hole in hydrogen tank and set it on fire, it will just burn (don't try to do this at home).
Right, the issue is though that in a collision you won't always just have a nice small controlled hole and burn.
I've worked around Hydrogen before, and storage was always a tricky issue. I remember the regulations stating something like needing to store the tank with either Argon or Nitrogen beside it. Not really something I'd want in the back, or any part for that matter, of my car.