The D platform, or D-body was Cadillac

Cadillac

Cadillac is an American luxury vehicle marque owned by General Motors . Cadillac vehicles are sold in over 50 countries and territories, but mostly in North America. Cadillac is currently the second oldest American automobile manufacturer behind fellow GM marque Buick and is among the oldest...

's full-size rear wheel drive 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 until 1996. It was closely related to the GM B platform

GM B platform

The B platform, or B-body, was General Motors' full-size rear-wheel drive automobile platform. It was closely related to the C-body and D-body and was used for coupés, sedans, and station wagons....

 and C platform

GM C platform

The General Motors C platform was an automobile platform designation used for full sized luxury cars until 2005.-Rear wheel drive:...

.

All D-bodies were built in Arlington, Texas

Arlington, Texas

Arlington is a city in Tarrant County, Texas within the Dallas–Fort Worth metropolitan area. According to the 2010 census results, the city had a population of 365,438, making it the third largest municipality in the Metroplex...

 from 1988-1996 model years. Earlier D-Bodies were produced at Detroit, Michigan

Detroit, Michigan

Detroit is the major city among the primary cultural, financial, and transportation centers in the Metro Detroit area, a region of 5.2 million people. As the seat of Wayne County, the city of Detroit is the largest city in the U.S. state of Michigan and serves as a major port on the Detroit River...

 in addition to Arlington for the 1977-1987 model years.

Originally, the D designation was exclusive to the Cadillac Fleetwood

Cadillac Fleetwood

Lawrence P. Fisher was the Fisher brother most closely involved with Cadillac in its early years. In 1916 he joined the Fisher Body Company which had been formed by two of his brothers in 1908. Larry was one of four of the seven Fisher brothers who brought Fisher Body Corporation under the General...

 75 series 9-passenger sedan and limousine with a 144.5" wheelbase. However when most GM full-size luxury cars moved to the front wheel drive GM C platform

GM C platform

The General Motors C platform was an automobile platform designation used for full sized luxury cars until 2005.-Rear wheel drive:...

 in 1985, the rear wheel drive Fleetwood Brougham

Cadillac Fleetwood Brougham

Lawrence P. Fisher was the Fisher brother most closely involved with Cadillac in its early years. In 1916 he joined the Fisher Body Company which had been formed by two of his brothers in 1908. Larry was one of four of the seven Fisher brothers who brought Fisher Body Corporation under the General...

 continued in production designated as a D-body using a 121.5 in wheelbase.

Production ended in 1996, leaving GM without a rear wheel drive luxury sedan. Later Cadillac introduced smaller cars on the Sigma platform

GM Sigma platform

Sigma is General Motors' mid-size rear-wheel drive automobile platform. The architecture debuted in 2002 with the 2003 Cadillac CTS and is adaptable for all-wheel drive and extended wheelbase versions...

.

Applications:

• 1977–1984 Cadillac Fleetwood Limousine
  Cadillac Fleetwood
  Lawrence P. Fisher was the Fisher brother most closely involved with Cadillac in its early years. In 1916 he joined the Fisher Body Company which had been formed by two of his brothers in 1908. Larry was one of four of the seven Fisher brothers who brought Fisher Body Corporation under the General...
  
  
• 1985–1986 Cadillac Fleetwood Brougham
  Cadillac Fleetwood
  Lawrence P. Fisher was the Fisher brother most closely involved with Cadillac in its early years. In 1916 he joined the Fisher Body Company which had been formed by two of his brothers in 1908. Larry was one of four of the seven Fisher brothers who brought Fisher Body Corporation under the General...
  
  
• 1987–1992 Cadillac Brougham
  Cadillac Brougham
  Originally an enclosed carriage, drawn by a single horse, for 2-4 persons, “Brougham” owes its name to a British statesman, Henry Brougham, 1st Baron Brougham and Vaux, whose second claim to fame is having given to the sea-front drive, in Nice in the South of France, the nick-name of Promenade des...
  
  
• 1993–1996 Cadillac Fleetwood
  Cadillac Fleetwood
  Lawrence P. Fisher was the Fisher brother most closely involved with Cadillac in its early years. In 1916 he joined the Fisher Body Company which had been formed by two of his brothers in 1908. Larry was one of four of the seven Fisher brothers who brought Fisher Body Corporation under the General...