The J platform was a designation used for two 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...

s from Chrysler Corporation in the 1980s.

The first was a rear-wheel drive platform, in production from 1980. It was very similar to the 4-door Chrysler F platform

Chrysler F platform

Chrysler's rear wheel drive F platform was used from 1976 to 1980. It was replaced by the nearly identical Chrysler M platform. There were two wheelbases: 108.7 in for 2-door models, and 112.7 in for four-doors. As the market evolved, these would be marketed as mid-size and eventually...

 and Chrysler M platform

Chrysler M platform

The M-Bodies were Chrysler Corporation's successor to the F-body Aspen/Volare. The platform, almost identical to the F, was introduced in 1977 and was the basis for some mid-sized Chrysler models until its demise in 1989. The M-body was also the successor to the short-lived R-body, as the Chrysler...

, which were based on the Chrysler A platform

Chrysler A platform

Chrysler's A platform was the basis for smaller rear wheel drive cars in the 1960s. These cars are sometimes referred to as A-body cars.Cars using the A platform in various markets around the world include:* 1960-1976 Plymouth Valiant...

.

The J platform was only used for coupé

Coupé

A coupé or coupe is a closed car body style , the precise definition of which varies from manufacturer to manufacturer, and over time...

s, and only for a few years:

• 1980-1983 Chrysler Cordoba
  Chrysler Cordoba
  The Chrysler Cordoba was an intermediate personal luxury coupe sold by Chrysler Corporation in North America from 1975-1983. It was the company's first model produced specifically for the personal luxury market and the first Chrysler-branded vehicle that was less than full-size.-History:In the...
  
  
• 1980-1983 Dodge Mirada
  Dodge Mirada
  The Dodge Mirada was a full-sized, rear-wheel drive coupe built from 1980–83, and was one of the three cars based on the Chrysler J platform, the other models being the second generation Chrysler Cordoba and the Imperial, these three vehicles being Chrysler's response to the downsizing of its car...
  
  
• 1981-1983 Imperial
  Imperial (automobile)
  Imperial was the Chrysler Corporation's luxury automobile brand between 1955 and 1975, with a brief reappearance in 1981 to 1983.The Imperial name had been used since 1926, but was never a separate make, just the top-of-the-line Chrysler. In 1955, the company decided to spin it off as its own make...
  
  

A second, unrelated, J platform, this time a variant of the front-wheel drive

Front-wheel drive

Front-wheel drive is a form of engine/transmission layout used in motor vehicles, where the engine drives the front wheels only. Most modern front-wheel drive vehicles feature a transverse engine, rather than the conventional longitudinal engine arrangement generally found in rear-wheel drive and...

 K platform

Chrysler K platform

The Chrysler Corporation's K-cars were compact-to-midsize cars designed to carry six adults on two bench seats and were aimed not only to replace Chrysler's nominally-compact F-body Aspen and Volaré, but also to compete with intermediates like the Chevrolet Malibu and Ford Fairmont...

, arrived in 1987 with the introduction of the new Chrysler LeBaron

Chrysler LeBaron

The Chrysler LeBaron was originally a classic luxury car of 1930s manufactured by Chrysler which competed with other luxury cars of the era such as Lincoln and Packard....

coupe and convertible. This platform remained in production until 1995.