The General Motors K platform (commonly called the K-body) was the automobile platform

Automobile platform

An automobile platform is a shared set of common design, engineering, and production efforts, as well as major components over a number of outwardly distinct models and even types of automobiles, often from different, but related marques...

 designation used for the rear wheel drive Cadillac Seville

Cadillac Seville

The Cadillac Seville is a luxury-type car that was manufactured by the Cadillac division of American automaker General Motors from 1975 to 2004, as a smaller-sized top-of-the-line Cadillac...

 models from 1975 to 1979.

The rear-wheel drive K platform was based on a heavily modified GM X platform

GM X platform

There have been two X-body automobile platforms from General Motors. All X-bodies were small entry-level models.-Rear wheel drive:The rear-wheel drive X-body underpinned the Chevrolet Nova and similar cars of the late 1960s and 1970s. It was also the basis for the Cadillac Seville's K platform...

 and shared components with the F-bodies

GM F platform

The F platform, or F-body, was General Motors' small rear-wheel drive automobile platform from 1967 until 2002. It was based partially on the GM X platform, which was used for compact applications instead of the sporting intent of the F-Body. The only two vehicles to have been built using the...

 of the 1970s. It used a stretched 114.3 in wheelbase, a simple front double A-arm suspension with a solid axle and leaf spring

Leaf spring

Originally called laminated or carriage spring, a leaf spring is a simple form of spring, commonly used for the suspension in wheeled vehicles...

s in the rear. The platform used unibody construction with a front subframe assembly, a design which first appeared in GM vehicles on the 1962 Chevy II.

In 1980, the Cadillac Seville was moved to the GM K platform (FWD)

GM K platform (FWD)

The General Motors K platform was an automobile platform designation used for front wheel drive Cadillac models beginning in 1980. It replaced the rear wheel drive K platform....

 platform, similar to the GM E platform

GM E platform

The General Motors E platform or E-Body was the automobile platform designation used for a number of personal luxury cars produced from 1963 to 2002...

-based Cadillac Eldorado

Cadillac Eldorado

The 1953 Eldorado was a special-bodied, low-production convertible . It was the production version of the 1952 El Dorado "Golden Anniversary" concept car, and borrowed bumper bullets from the 1951 GM Le Sabre show car...

.