Cadillac's finned era started with the 1949 model. We'll post a few of those later.
Here are two examples where flamboyancy cruised the boulevard in 1958, top.The 1959 Caddy, of course, is celebrated or ostracized for its excess. Those lenses were quite exposed.
Chrysler became devoted to fins as well. Ford seemed more subdued as were some of the GM makes as well.
By the mid 1970s, the fascination with fins became passe', and rear fenders lost their allure, no longer the subject for comment.