I can see Corvairs not being popular in the mountains. In the flat Midwest they probably sold much better. Had a high school teacher in the 80s that had a '63 Monza convertible. He brought it to school once a year and showed his classes. He used to try to tell everyone it ran on rubber bands.

I don't think Corvans were common anywhere. I saw lot of Econolines and A100's well into the 80's though. My aunt and uncle had a A100 they nicknamed the "Hippy Bus."