The M-body years

In 1980, a Fifth Avenue package was created by ASC (American Sunroof Corporation) for the Chrysler LeBaron, which shared its platform with the Dodge Diplomat. This rare option package, produced on 654 LeBarons for the year, included many of the exterior features found on the New Yorker Fifth Avenue in a smaller, more sensible package.
With the R-body out of production and the LeBaron name transferred to the Chrysler K platform, the New Yorker was downsized again for 1982, becoming a mid-size model. The Fifth Avenue option was still available. It was adapted from the earlier LeBaron's package, with a distinctive vinyl roof, opera lamps, and a rear fascia adapted from the Dodge Diplomat, albeit modified. Interiors featured button-tufted, pillowy seats covered in either "Kimberley velvet" or "Corinthian leather", choices that would continue unchanged throughout the car's run.
For 1983, the New Yorker and the Fifth Avenue diverged. The New Yorker was downsized yet again, and became a front-wheel drive car equipped with a four-cylinder engine. The previous car was now called New Yorker Fifth Avenue, this would be the last year M-bodies were made in Canada and the last year for the optional "Chronometer" glovebox mounted clock, 1983 was also the last year the 225 Slant-six engine was offered. The optional 8-Track player and CB radio were no longer offered nor was the 175 hp (130 kW) 4 barrel 318 (though it would still be used in police M-bodies)
For 1984 it was simply called Fifth Avenue. The rear-wheel drive Fifth Avenue would continue for six successful years and would prove to be the last V8-powered, rear wheel drive Chrysler until the Chrysler 300 was revived in that configuration for 2005. All Fifth Avenues from 1984 to 1989 were powered by a 5.2 L (318 in³) V8 engine mated to Chrysler's well-known Torqueflite automatic transmission.
Production Figures by Year:
1983    83,501
1984    79,441
1985    109,971
1986    104,744
1987    70,579
1988    43,486
1989    26,883
Grand Total    518,605
Although it takes a trained eye to catch changes in the M-body Fifth Avenue, there were a few during its six-year run:
1984 - New Yorker badge replaced by Fifth Avenue badge on trunklid; "Fifth Avenue Edition" badge continues on the rear doors, a new steering wheel was added. There were also no more analog tuned radios
1985 - New black gearshift knob introduced (1982 to 1984 models have chromed knobs). Turn signal lever is now also black (1984 and below models were interior color keyed).
1986 - New-style ignition key and center high-mounted stop lamp (the latter a federal mandate) introduced.
1987 - New steering wheel, last year alloy wheels and two-tone paint were offered.
1988 - Vinyl roof restyled; lower edge of sail panel covering extended below chrome window sill moldings. "Fifth Avenue Edition" badge replaced by a crystal Pentastar surrounded by a gold wreath. Most chrome interior trim vanished. Shag carpets were no more. Driver's side seat now had a manual recliner (previous models had 6-way power adjusters, but no recliner). Driver's side airbag became optional mid year. Door panels are restyled and power mirrors are standard. Overhead console became available.
1989 - Driver's side airbag is standard.