Keeping more to the original point, installing a sodium battery in a car will be more ecologically and otherwise beneficial - materials are more common and less environmentally damaging to acquire, battery has a longer lifespan, and can operate much better at low temperature, reducing the need of pre-heating during winters. All of these are not only convenient, but environmentally positive.

The only downside, and the reason sodium-ion batteries are not everywhere, is that the range under normal conditions would be lower. Still, it does crawl into automotive tech thanks to Chinese manufacturers. I think it's a good development, and one I watch more than new advancements in lithium.