Like the 1956 Seville, the 1957 model was a remodeled version of the Series 62 Hardtop with an extensive trim package and new rear bodywork. In 1957, the new rear bodywork was much more bulbous and which pushed the fins more towards the center of the car. This look would define the 1957 and 1958 Eldorados.
Small differences from the 1957 version included Eldorado scipts on the hood and trunk above the Cadillac gold V. The fender script was relocated from behind the wheel arch to the top, near the headlights. There were also two front fender fins that were attached to the top of the fenders.
Cadillac described the 1958 model in their brochure as “remindful of the “dream cars” appears on this 1957 Eldorado Biarritz Convertible. Not only are the fins set inboard on the smoothly contoured body but the bumper is built in and wraps around to the rear wheel openings. Biarritz owners have a choice of two engines; the high performance 300 horsepower Cadillac engine or a modified version which develops 325 horsepower.”