I think your analysis is right, but I don't think you should limit it to self driving cars.

Take remote work. Currently it's not the norm but it's becoming more and more popular. When/If it's the norm, we will have:

remote worker becomes the norm => no need to live closed to the work places => no need to live in big cities were real estate is expensive => some people will move out

I don't think technological progress making the real estate prices go down would be a bad thing, quite the opposite.