We also need EV designs where the batteries are modular and easy to swap out. I wouldn't be interested in a deal where I was compensated financially for quickly wearing my non-replaceable car battery out, because the battery wear alters the usability of the car, e.g. I might find I can only take my family on shorter trips than planned, if my battery is now 80% of what it would have been.

I also wouldn't want the battery level timed around the grid vs my own transportation needs. What if there is suddenly a heavy demand on the grid, and now I can't take my sick family member to the hospital, because the charge was sold to the grid?