In 1977, Mercury made Cougar a full line of cars, including this 4 door pillared hardtop and a wagon, as well as the XR-7 personal luxury coupe and a regular 2 door hardtop. From its Pony car roots, based on the Mustang, to a mid-size luxury coupe in '74 to being the entire mid-size line in '77, this was just several Cougars too far beyond the edge, lol. They weren't bad cars at all, they were quite nice cars for the time, with a great ride, great features and not all that bad on the eyes for that period. They just weren't Cougars, in my opinion. I think Mercury had a fine enough name with the Montego and should have left them as such.
Interestingly, the phrase "Jump the Shark" originated in 1977 also, referring to an episode of "Happy Days" that went too far, with The Fonz water skiing on-air. Link here.
The 4 door was available as a luxury Brougham trim level, almost equal with the Marquis in feature content and luxury options. This was during the "downsizing" era, and was an obvious stopgap since Ford wouldn't have any actual downsized cars until 1980, unless you count the Thunderbird of 1977. That Tbird was a thinlypveiled Torino, which itself had been renamed the LTD II to seem as if it was a downsized full sized car, which of course it wasn't. Tbird sales skyrocketed over the '76 version, but Cougar sales went nowhere.
I don't care how many times you use "sporty" in a description, this two-ton 4 door station wagon just wasn't sporty and never would be. Was this a nice station wagon? Of course. It had the woodgrained sides, which was always a classy touch in my opinion. The interior could be optioned fully, including those Twin-Comfort lounge seats with dual fold down armrests, and all the power accessories one could wish for were available. Again, considering the classic Cougar of 1967, this just wasn't, and never could be, a real Cougar.