I agree with Harry about the Corvair as a significant car, but more for what it precipitated in the auto industry, than for its rear engine design. If what I heard is true, it was the success of the sporty Corvair Spyder (esp. with turbo option) that prompted Lee Iacocca to produce the Mustang. That, of course, led quickly to the whole Ponycar/Musclecar/performance car race and culture that persists to this day, and provides subjects for about half the models on this forum!
Sam