I would think that car rentals would be one of the slowest areas for electric adoption. You're immediately limited to people only intending to drive short distances, which is less common for car rentals than day-to-day car ownership. Of those, many will be people far from home where they're not familiar with the charging infrastructure. Maybe they can stay at a hotel with chargers, but what if there are only a couple and they don't get one one night? It just sounds like a way to make planning a trip more complicated.