I read several articles that Mitsu seriously considered adding a turbo for the sedan.
Then apparently they did focus groups with existing Mirage owners in the States, and nobody really complained about engine power. They (Mitsu) admitted some surprise at that.
I also asked Mitsu Canada's PR person if there was any chance we'd ever see a turbo and he said "nope".
Sadface.
It would be better for the Mirage community if one were available. Maybe for sales too - they didn't ask people who DIDN'T buy the car if it needed more power.
Oh, the paucity of choice! Back in the day, even the Metro/Suzukiclone lineup had 5 (FIVE!) distinct engines to choose from at various points, including a turbo triple.
There have been a few aftermarket turbos slapped on some Mirages by owners though - even an EVO drivetrain swap.