1980 Ford Thunderbird and Mercury Cougar

Those 1980-1982 8th-generation Ford Thunderbirds and 5th-generation Mercury Cougars sold poorly compared to equivalent previous and subsequent cars.  For example, 284,141 Thunderbirds were produced in 1979 followed by 156,803 in 1980.  By 1982, only 45,142 were built.  The new aerodynamically styled 1983 model tallied 121,999 units.  Respective numbers for Cougars were 166,547, 58,028 and 75,743.  I should note that these featured cars were marketed during a major economic recession, and that would have accounted for some of the lower sales levels.

Note that while Thunderbirds were only coupes since model year 1966, Cougars were originally coupes, but evolved into a line with several body types for 1977-1979, reverting to only coupes starting 1980.  That might have created some confusion regarding what "Cougar" meant in the minds of some potential buyers.

Cougars were generally priced lower than Thunderbirds, being simply a sporty line in the mid-range Mercury brand's portfolio.  Thunderbirds, on the other hand, had a product history of being sporty in special ways.  The first Thunderbirds were two-passenger cars.  These were replaced by four-passenger cars with unique styling and continued sporty flair (scroll upwards on the link above for some history).

What went wrong with those 1980-1982 Thunderbirds and Cougars?  Though their styling was contemporary and attractive, they just seemed ordinary.

Gallery

1980 Thunderbird - Mecum Auctions photo
Shorter than previous-generation Thunderbirds, the design is mainstream 1970s angularity with a visually low main body and tall passenger compartment greenhouse.  Note the not-rounded wheel openings that continue the basic theme.  Also the strong character sculpting on the side of an otherwise simple design.  The main "ornamentation" seen here is the vinyl roof covering.

1980 Cougar XR-7 - car-for-sale photo
Cougars differed little from Thunderbirds.  The after side windows are partly covered by decorative louvers.  The car shown here lacks vinyl, though vinyl was common on Cougars.

1980 Thunderbird - car-for-sale photos
Hoods on these cars were commendably long.  Those rectangular headlights helped support the angular styling theme.

1980 Cougar - car-for-sale photos
This Cougar's grille rests in the same frame as the Thunderbirds, but the bolder vertical bars on it recall the vertical-bars theme on post- World War 2 Mercurys.  Headlights are rectangular quads.  The fender-front lighting is less elaborate than that seen on the Thunderbird in the previous image.

More side-views.

Vinyl on Cougars covered only the after part of their roofs, unlike the full coverage on Thunderbirds.

Thunderbird aft ends featured wide taillight/reflector assemblies since 1967. 
The design seen here is similar to that found on 7th-generation models.

Cougars had taillights separated by the trunk lid.  Otherwise, rear ends are structurally about the same.  The vinyl on the Cougar encroaches on the backlight window, whereas the Thunderbird's does not.