What is the advantage of a rear engine car?

Most of the cars you mention are mid engine. The 911 is a rear engine and the Corvairs that everyone else mentioned are rear engine. In a mid engine, the engine is behind the driver but forward of the rear axles. The rear engined cars are best on snow and ice, the mid engine cars are capable of the best handling, but in both cases, they are tricky to drive and if you are not trained in them, you can get into serious trouble quickly. Not good for average drivers.