Also, most charging will happen at home, at night.

I doubt that; PV is cheap compared to storage, so it makes more sense to install twice as much PV as needed and include the charging plugs in existing car parks (and waste some power during commuting and lunch breaks), than to add enough immobile storage to allow most car charging to happen at night.

The thing about nighttime is that thats when the car isn't moving around much. Best time to charge.

Only when the power doesn’t come from PV. If it does, you need (three?) times as much battery capacity: the car’s battery, the immobile battery that the car charges from, and the battery which powers your houses (and some industry and commerce) overnight. If you charge your cars during the day, you can use some of the battery capacity in the electric cars, partially discharging some of them overnight to supply your nighttime needs.

Yeah I see what you mean. Maybe everyone will need to commute nocturnally once we're running everything on solar!

So one year the defense budget.

Seems possible