I agree.
I had to look it up to see if it ever happened. To my surprise, it did. Three times, the best I can tell. 1967, 74 & 75.
@Skoalbandit33, your and my hero, Richard Petty, even managed to average 5.0, 4.2 & 4.7 over those three years. That's freakin awesome, and also something that I wouldn't have know without looking it up. During those three years he amassed 56 wins. To think, had we had today's format, he may have not won the championship in two of those years. The other year he finished first in the last race. We may be looking at The King as a five time champion had that been the case. That would be about right in some people's book. Not mine.
Again, this only further magnifies the ridiculousness of the current format. Is ridiculousness even a word? Hey, it works.