Let's start in the short term. Most cars are not driven by professionals, this means that if we can come up with one to many jobs related to these new cars they may be absorbed by the dislocated work force. The first of these jobs is UAC pilots for when cars get into trouble. Secondly these cars will likely have a much lower tolerance of dysfunction then people have with their cars, so the need for mechanics will rise. And really where the magic is with that translation is that this change will be spread equally over the cars that are professionally driven and those that aren't so it won't need to be a 1-1 exchange for jobs.
Now to look at what happens as robots take over everything.
First thing to do, expand. The needs of how many people or service people a mostly automated society can take care of are bounded by the geographical area that the people are in. So if we decrease density and expand we can grow human jobs that way. Of course this means expanding int new types of areas which will require new types of innovations so the innovation sector will expand.
The second thing to do is change the education system. As economic activities are increasingly reduced to ownership, innovation, and education, we need to move increasingly towards free educations and then towards paying people to become educated ( rewarding higher levels of pursued education with higher compensation). So that as industries die, those that can are motivated to move up the path of education. That way we will always move towards a maximized innovator class and move people to their optimal level of innovation so that people who can learn more don't take away opportunities from people that are maxed out.
The third thing, is to avoid the accumulation of ownership into the hands of individuals. One way to do this is to adjust the rules for inheritance, to favor the distribution of inherited wealth both to as many parties as possible and to those that are not already wealthy. And if anything is left to fall to the state, either hold it in a social trust, or distribute it as possible, depending on your politics.
The fourth thing you do is to manage the population in both directions. If there are too many people you increase the disincentives toward childbirth. If there are too few people, you make it a pro to have kids.
You don't do all of those things overnight so we need to start moving in those directions before we are too messed up. But maybe I'm completely wrong. Those are just my ideas.