We (somewhat) have. I was part of a focus/design thinking group for VW working on this. I think what’s mostly holding it back right now is the relative low pre

We (somewhat) have. I was part of a focus/design thinking group for VW working on this. I think what’s mostly holding it back right now is the relative low prevalence of electric cars and that, as far as I can tell, we have not yet reached the point where renewable energy actually needs batteries. The scheme only makes sense when Wind & Solar actually exceeds demand for significant stretches of time. After that, there are some issues: car manufacturers need to somehow find a scheme for them to make it worthwhile for them. Owners need to be compensated at least for whatever wear it inflicts on batteries. They had simulations showing the scheduling would actually be somewhat easy. This was three or four years ago, and their algorithms were already almost perfect in predicting when you would need your car.