Depreciation is variable though, and dependent on fair market value at lease termination. If Tesla designed the car with a part and sold said part, everyone wo

Depreciation is variable though, and dependent on fair market value at lease termination. If Tesla designed the car with a part and sold said part, everyone would be better off: Tesla (less risk of catastrophic repair expenses), insurance companies (lower repair costs, less variability), and the customer (cheaper repairs and insurance). I get that's not a trivial request, but other car manufacturers manage the task.