I’m not sure to the answer to this question, I don’t think anyone in the world is yet.
There are some vehicles that can’t be powered (yet) with bio-ethanol like ships and aeroplanes, they use different kinds of fuels that aren’t similar enough to ethanol.
As for whether bio-ethanol could power all of the cars in the world, again I’m not sure. The question is whether we have enough woody lignocellulosic material to use to make bio-ethanol out of. The amount of this material available however would probably change (increase) once using it becomes common because it will become more profitable for the farmer. There is lots of land in the world which isn’t good enough to grow food crops on, but probably would be good enough to grow *something* on which could be used to make bio-ethanol and we would probably see this land become used more and more as making bio-ethanol becomes more common.
I hope that helps, again feel free to ask more questions if you like.