There was a racetrack on the roof of the Fiat factory in Turin
As it was first baptized, Fiat, or Fabbrica Italiana di Automobili Torino, is still an integral player in Italy’s economy. Their first automobile was produced in 1899, and by 1910 they were the largest automotive company in the country. The Lingotto building, one of its most famous factories, was inaugurated in 1923.
As you can see in this picture, it had a track on the rooftop. The raw materials were brought into the first floor, and everything was sent upwards, with each level serving a different part of the assembly process. The factory became obsolete in the late 1970s and was finally closed down in 1982.