text: Second generation (1980) The 1980 model year brought new exterior sheet metal for the Diplomat, although wagons were unchanged from the doors back. While the previous coupes used the same 112.7 inch wheelbase as the other models, the 1980 coupe used the 108 inch wheelbase of the Aspen coupe (though the square body was very different).  The front end was more evolutionary than revolutionary, but in order to share a hood with the newly restyled Chrysler LeBaron the grille was narrowed considerably.  The roofline of the sedan was also made more square, marginally improving headroom, and conservative, Buick-like taillights appeared on all but the wagons.  Manual transmissions were dropped. Following the discontinuing of the Dodge St. Regis R-body in 1981, the Diplomat became the largest sedan in the Dodge lineup, despite technically being a mid-size car. Dodge would not market another truly full-size car (at least based upon United States Environmental Protection Agency (EPA) passenger volume statistics) until the Monaco debuted as a 1990 model.
  By 1981, Chrysler was switching to smaller front-wheel drive designs. However, its older and larger rear-wheel drive Dodge Diplomat (as well as the Chrysler LeBaron and Fifth Avenue) continued to sell. Chrysler's then executive vice president for manufacturing, Steve Sharf, met with officials at American Motors (AMC) to use the extra capacity at an assembly plant in Kenosha, Wisconsin to build the cars. Chrysler's tooling was moved from St. Louis to Kenosha, and from 1987 until 1989 about 250,000 Chrysler and Dodge models were built by AMC at a lower cost than Chrysler could. This relationship evolved into Chrysler's purchase of AMC in 1987.