I just finished reading about Ford's Lincoln Continental Mk. II., a beautiful luxury car that went into production. I always thought that it was the recession that killed it, but apparently Henry Ford II and his brother William [[who was behind the Mk. II) got into a sibling pissing contest over the car. Long story short, the Mk. II and its designated successor, the Mk. III) were killed by several underhanded ways. The hideous '58 Continental replaced it.

My armchair guess regarding the Chevrolet pictured above is that the money men running GM squashed it. I think that only John DeLorean could have pulled off something like that in GM.