Frog,
I dont think his crusade was even aimed at a specific year.
The problem with rear engined cars, as Lazs pointed out, is that you cannot brake while turning or you will snap oversteer and it takes alot of seat time to avoid - or use - understeer under throttle while turning.
With all the weight in the back of the car (911, Corvair, Bug) the rear end will swing like a pendulum when traction is broken.
For an amature driver, its a serious issue. For a professional pilot, it allows him to do things not possible with a front engined car on a race track.
Nader needed publicity - the Corvair was an awesome ride and still has a very strong cult following today.