It's hard to imagine a world without the BMW M5. The super sedan made its mark back in 1984 as a serious sports car capable of providing both performance and the practicality of a four-door sedan. But before the M5 was introduced to the world, BMW's M division created a super sedan called the M535i. Built in 1980 and 1981, the sedan packed a 3.5L inline-six with 218 horsepower and a five-speed gearbox. Performance was astonishing for the time with 0-62 MPH taking a mere 7.5 seconds.
BMW has released a short video talking about this special 5-Series and how it set the stage for the M5 a few years later.