I am not sure that battery production could scale up to 50 millions vehicle produced each year, without mentioning we will also need to replace a significant part of the installed base regularly. We can however hope that self driving car would significantly reduce the number of car needed.

Self-driving cars would not reduce not number of cars produced. If anything, it would increase it, since going somewhere would become easier.

Self-driving cars may change the model from "everyone needs one" to Uber-esque "there's a shared fleet, one shows up when you ask" model.

All electric cars take hours to charge off of 120v or 240v mains at up to 10kw. There's no way you're powering your car with even a garage roof full of solar cells this way, unless you want to wait days for the car to charge. 85 kwh is a lot of capacity to fill.

But if your solar panels are generating energy and storing it in a large capacitor (like Bloom Energy does) for later release, then it could -- in theory, at least -- be pushed to the car much faster than a standard 120/240v main.

You could buy a Nissan Leaf, which I think the the most efficient mainstream electric, and build out a really nice solar array and charge up more than a few miles a day, but the cost of that array is going to be pretty rough. All said and done probably more than the car. That's just not feasible for most.