What is the safest car?

Self Driving and Driver Assist Technology

Originally posted on the forum by James121:

I noticed that you focused a lot on safety features in your reasons for self driving cars. It seems that having the collision avoidance features may prevent a lot of front end collisions. I suspect there may be other safety features that some manufacturers use, such as how they construct the cars and the materials used.

Is there any good study on the actual safest car, or do you think the crash tests and the IIHS ratings are really the best indication of the safest car?