Oh, but what about wealthy corporations rendering autonomous vehicle services, either as their primary offering, or as an ancillary side business?

You could own shares in such a company, purchase a subscription to summon vehicles at a rate, or buy a vehicle and resell its autonomy, offsetting the expense. One might view some of these options as a form of collective ownership, and so it might not just be you owning one on your own, but maybe contributing to the partial ownership of one or more vehicles.