Lamborghini started producing tractors at first. Here on I quote from www.thefreedictionary.com
As told by Ferruccio Lamborghini's son, Ferruccio Lamborghini went to meet Enzo Ferrari at the Ferrari factory to complain about the quality of the clutch in the Ferrari 250 GT he owned. Enzo Ferrari sent him away telling him to go and drive tractors because he was not able to drive cars. Lamborghini went back to his factory, had his Ferrari's clutch dismantled and realized that the clutch manufacturer was the same who supplied the clutches for his tractors. In his warehouse he found a spare part which he thought suitable, and when it was installed the problem was solved. Furious with what he considered to be Enzo Ferrari's arrogant and aloof treatment Ferrucio Lamborghini promised himself never to go back to Ferrari for another car but rather beat him at his own game by creating a superior sports car. Thus the idea of a Lamborghini sports car was born.