Complex sentence: Rover SD1 is both the code name and eventual production name given to a series of large executive cars made by British Leyland or BL through its Specialist, Rover Triumph and Austin Rover divisions from 1976 until 1986.
Split into simpler sentences: Rover SD1 is both the code name and eventual production name given to a series of large executive cars made by British Leyland (BL), under the Rover marque. It was made through its Specialist, Rover Triumph and Austin Rover divisions from 1976 until 1986.