Take out the drivers and you have a company that makes short term rentals of automobiles to consumers. There are already companies that do this. You may have rented a car from one of them last time you traveled. Take a look at Hertz or Budget and see if those are companies you actually want to be invested in.

And regarding patents: what will probably end up happening with self-driving patents is that there will be a bunch of different entities (everyone currently working on self-driving tech) that will cross license their IP to each other. A patent in this space is going to be good for licensing fees, but not for giving yourself a monopoly on self-driving tech.