Vehicle integrity is the responsibility of the driver for human driven cars, I assume it would be the same for autonomous vehicles. The problem comes when you are driving a 15 year old car because you can afford new. For non autonomous vehicles mechanical safety is dependent on powertrain, steering, and brakes, all of which are under manual control. Maintaining the integrity of autonomous system--its computer, its sensors, its radar/gps, the accuracy of its maps, will be even more important than the maintenance of those manual system.