So, someone shooting a paint gun counts as “dystopian future”? These are the lowest-grade irrational fears I’ve seen in a long, long time. And there’s nothing you described that couldn’t be done to a parked car right now, but that doesn’t happen, because people generally aren’t maniacs looking to destroy things for no reason.
The real danger of self-driving cars is all the people who get put out of work, and what happens to them. We didn’t do a great job of dealing with the consequences of factories closing; the working class is going to be a lot angrier if every driver’s job is eliminated in 20 years.