Not only can consumers not maintain the software in their self-driving car, under the DMCA it is criminal for them to even attempt to do so! And it is the software that is the distinguishing characteristic of a fully autonomous self-driving car.
> Not only can consumers not maintain the software in their self-driving car
(1) Maintaining a self-driving car is more than maintaining software,
(2) Even in the case of software, an owner might have responsibilities with regard to maintenance (not in the sense of "maintaining software" in the programming sense, but in the sense of ensuring that, e.g., updates released by the manufacturer are downloaded and installed -- even if this is an automated, the owner may be responsible for making sure the vehicle is kept where that process can successfully complete and not interfering with it.)
> And it is the software that is the distinguishing characteristic of a fully autonomous self-driving car.
The "distinguishing characteristic" of a self-driving car is not the only thing relevant to liability.