The cars were available as both 2 door coupes and 4 door sedans. Engine options ranged from a 200 cubic inch six cylinder all the way up to a 351 cubic inch V8. There were Ghia models, which offered upscale trim and better sound insulation.
The rarest of these cars is the 1977 1/2 Granada Sports Coupe. I've never actually seen one of these, but I have seen advertising of this model from that period. There was a wagon version of the car during its final year in 1982. After that, the line was renamed and moved to the Fox platform. The Mercury Monarch became the Mercury Cougar, bringing back a name that had been popular during the muscle car era.
You can still find these cars listed on eBay. They are not quite what I would call collectible, but some models are certainly very cool and unusual.