I think the logistics for battery swapping in bikes vs cars is completely different. A battery in a car is a critical piece of mechanical equipment, that lower

I think the logistics for battery swapping in bikes vs cars is completely different. A battery in a car is a critical piece of mechanical equipment, that lowers CG, forms an important part of the stability calculations etc. As such, the fixtures that hold a car battery in place are much more rugged and designed so. Making that a swappable design adds more weight to an already overweight car (for example, having a rugged frame casing that has a removable batter inside)