1957 saw the Eldorado (in both Biarritz convertible and Seville hardtop bodystyles) with a revised rear-end design featuring a low, downswept fenderline capped by a pointed, in-board fin. The rear fenders were commonly referred to as "chipmunk cheeks". This concept was used for two years, but did not spawn any imitators. Series 62 Eldorados (as distinct from the Series 70 Eldorado Brougham) were further distinguished by the model name above a V-shaped rear deck ornament and on the front fenders. The rear fender and deck contour was trimmed with broad, sculptured stainless steel beauty panels. Also seen were "shark" style fins pointing towards the back of the cars. A three section built in front bumper was another exclusive trait of the Series 62 Eldorados, which came with a long list of standard features. Four specially-built 4-door hardtop Eldorado Sedan Sevilles were also built in 1957.
1957 was chiefly notable for the introduction of one of GM's most memorable designs, the Series 70 Eldorado Brougham. Announced in December 1956 and released around March 1957, the Eldorado Brougham was a hand-built, limited car derived from the Park Avenue and Orleans show cars of 1953-54. Designed by Ed Glowacke, it featured the first appearance of quad headlights and totally unique trim. The exterior ornamentation included wide, ribbed lower rear quarter beauty panels extending along the rocker sills and rectangularly sculptured side body "cove" highlighted with five horizontal windsplits on the rear doors. Tail styling treatments followed the Eldorado pattern. This four-door hardtop with rear-hinged rear doors was an ultra-luxury car that cost an astonishing $13,074 — twice the price of any other 1957 Eldorado and more than the Rolls-Royce Silver Cloud of the same year.
It featured a stainless steel roof, self leveling air suspension, the first automatic two-position "memory" power seats, a dual four-barrel V-8, low-profile tires with thin white-walls, automatic trunk opener, cruise control, high-pressure cooling system, polarized sun visors, electric antenna, automatic-release parking brake, electric door locks, dual heating system, silver magnetized glovebox, drink tumblers, cigarette and tissue dispensers, lipstick and cologne, ladies' compact with powder puff, mirror and matching leather notebook, comb and mirror, Arpège atomizer with Lanvin perfume, automatic starter with restart function, Autronic Eye, drum-type electric clock, power windows, forged aluminum wheels and air conditioning. Buyers of Broughams had a choice of 44 full-leather interior and trim combinations and could select such items as Mouton, Karakul or lambskin carpeting.