[Edd Beesley]

I suppose the H2 i3 could lose some (most) of it's battery to gain some volume for H2 storage, and the place where the petrol rex lives is where the fuel cell stack goes.

Still, don't have a hydrogen tap at my house, so don't really care if they make it or not!

 

[Edd Beesley]

There could be multiple tanks, laid flat as cylinders, I seem to remember seeing so e hydrogen car prototypes like that.