I guess it depends on what you mean by 'most ideal'. For mass production cars, the benefit of a rear-engine, rear-drive layout was that it was low cost. The drivetrain is often smaller and lighter and can be packaged with the gearbox for easy assembly. A big advantage of doing it this way is that passengers get maximum interior space. For many, the Porsche 911 will probably be considered the best rear-engined car - on the 993, this used an all-alloy multilink rear suspension.