I see a common focal "point" here:

I'm not sure where the design impetus really was heading from the early 50's-early 60's, but I think the Dagmars of the 50's were being transformed into a more PG space-age motif. Thus this:

- Dagmar Evolution.png (185.25 KiB) Viewed 3903 times
became this:

- bullet bird,olds rocket exhausts.jpg (33.21 KiB) Viewed 3903 times
But, sadly, my first cars were 56 Chevies, and I suffered from Dagmar envy:

- 56 chevy points.png (169.57 KiB) Viewed 3903 times
as the '56(s) were underdeveloped. However, I soon discovered the real thing, so I was able to deal with it.