2) It's a bad proposition to people because you're basically telling them they won't be able to take long trips in the morning and you're going to decrease the life of their battery (people are rightfully really concerned about this).
3) The big concern with utilities right now is how to handle home renewable excess power during the day. All the rooftop PV is feeding a bunch of power back into the grid when it's sunny, then all those homes are sucking down power from dusk to dawn. The utilities need daytime power storage or non-daylight generation to offset this. Storing power at night doesn't do much to actually solve the problem, so there's not much of a business model in it. Grid-scale battery installations are quickly becoming the solution here.
If you're looking for a car-based model that could potentially work for this, it has to involve solar parking lots and also be car-specific. Charge your car at a parking lot during the day, drive it home and plug it in to power your house in the evening. Get a discount from your electric company as a result.
You can just buy batteries for your house. We’re down to what? $200/kWh? Less? If there wasn’t so much mark up in the industry, you could buy a whole house battery for 2-3k that would be good enough to shift most of your energy usage. Utilities just need to incentivize it, which presumably would happen naturally due to market forces as solar adoption goes up.