When that happens, auto insurance rates will be adjusted accordingly for autonomous vehicles, and soon you'll find that manual driving is not only expensive, but even illegal in many areas.
This is absurd. Do you realize how many people drive for recreation/sport? Most residential areas are not conveniently located near a closed race circuit, and where such facilities do exist, it's typically quite expensive to use them. The point of the sports car is to add enjoyment to an otherwise mundane driving experience, and to do so by using the car on public roads. This will not change. People will continue to drive human-controlled cars through 2020 and beyond.