2 huge problems straight off the bat are where and how do people charge who live in either high rise buildings/flats/apartments and those with no off street parking?. That's just 2 easy ones that nobody can answer.
The biggest one I see though is, where does all the extra draw to the grid come from?
Or the cables under the road. I think most people would be shocked when they see the incoming lines that are feeding an entire street or estate. You would be expecting some mega fat chunky things but they aren’t. If 20 people turned on their kettle at the same time it would melt the underground wire. Now imagine a whole street full sticking 3x that load into their car all at the same time. The cost in rebuilding the entire grid from source to the end would be astronomical.