My parents neighbor had a Chrysler Imperial. It was black with suicide doors on the back. Not sure the year. He only drove it in the summer. He would jack it up and take the wheels off in the winter. Of course, it had white walls. It looked like a mafia staff car.
Are you sure it wasn't a Lincoln Continental? They have a similar look to the Imperial, and were manufactured with suicide rear doors. I don't recall any Imperial models with suicide doors as an option. All the pictures I can find with four-door Imperials all show normal doors.