One thing we always like to see is the concept version of a car before it becomes reality. It’s neat to see what stays, what changed, and what could have been. Check out this picture of the 1955 Bel Air concept car. You can see the general shape stayed the same but features were updated and changed before final production.
The ’55 Chevy Bel Air has design ques from the ’53 Cadillac along with the ’54 Olds and Buick. You have to think that back then, things started at the top with Cadillac, then trickled their way down to Chevrolet. It’s no unusual to see things in earlier Cadillacs that appear in later Chevrolets.