For the 1980 model year, Cadillac moved the Seville to the 114 in (2,900 mm) wheelbase K-body, based on the front-wheel drive E-body Eldorado, Buick Riviera and Oldsmobile Toronado. Returning to some of the original concepts floated for the 1975 edition (the March 2008 issue of Collectible Automobile featured an early concept of what evolved into the downsized 1977 Cadillac DeVilles and Fleetwoods — one of the concepts which was withdrawn looks similar to the second-generation Seville), The rear styling was intended to invoke the look of Daimlers of a past era (though British Leyland were building cars with this feature even then). In the U.S., The bustle-back styling was imitated by the 1982–1987 Lincoln Continental sedan, and the 1981–1983 Chrysler Imperial coupe.
The new model, one of the last vehicles designed by GM's Bill Mitchell, featured front-wheel drive and independent rear suspension. The Seville initiated features that would become more traditional in later years. In 1981, "memory seats" — a feature not seen on a Cadillac since the Eldorado Broughams of the late 50's — became available again. This option allowed two memorized positions to be recalled at the touch of a button. Also for 1981 was a digital instrument cluster. The "Cadillac Trip Computer" was a precursor to this option in 1979. For the '81-'85 Seville and Eldorado, it was considerably less expensive, at US$200 in '81, and did not contain the many features of Trip Computer, but rather, just a digital speedometer and fuel gauge. "Puncture-sealing" tires were also new for '81. In 1982, Seville offered heated outside rear-view mirrors with the rear defogger option. Inside, a "Symphony Sound" stereo tape system was available. For 1983, a new "Delco/Bose" stereo cassette system was offered at US$895. It featured a brushed gold-look front panel and bulbous lower interior door speaker assemblies giving almost an aftermarket installation look to the system. This was also the last year for the availability of an 8-track stereo system for Seville. On the outside, Seville was available with a "Full Cabriolet Roof" treatment option, which gave Seville the dashing look of a four-door convertible. Cadillac may have provided this due to the popularity of a similar option, available since 1979, on the Lincoln Continental automobiles and Cadillac's own "Phaeton" series of De Ville models in 1978 and 1979.