The other big reason that Targa Florio is so important to Alfisti is that it is where the four leaf clover logo came from.
Yeah, I thought it was an Irish thing, but it's not. The year was 1920. Alfa Romeo had build their team of race drivers: Enzo Ferrari, Ugo Sivocci, Giuseppe Campari and Antonio Ascari. Ugh Sivocci had the dubious distinction of not winning races. In fact, he had the nickname of "L'eterno Secundo", which as you can probably surmise means 'Eternally Second". By all accounts it wasn't his fault, by all accounts he was a fast and experienced driver prone to mechanical failures.
Ugo Sivocci drove the Alfa Romeo RL. He was was sick and tired of getting second place and probably equally tired of his nickname. The Targa Florio was coming up and he was determined to change his luck, so he had a local sign painter come out and paint a diamond and a four leaf clover on his car; he won the race. That day, the other Alfa Romeo drivers won second and fourth as well, firmly established the racing heritage that is Alfa Romeo. From that day forward, Ugo Sivocci would make sure to have a four leaf clover within a white diamond painted on his car before every race.
Later that year, at the Italian Grand Prix, was held at Monza. However, the painter that was supposed to come down to paint the clover on Sivocci's car didn't show up. Sivocci went out on track for the practice session. Ugh Sivocci died when his car crashed during that practice.
Out of respect for Sivocci, Alfa Romeo withdrew the rest of their cars from the Grand Prix and Sivocci's car number, 17, would never again be worn by an Italian race car. They kept the four leaf clover, but the white diamond background was changed to a triangle in order to symbolize the loss of of one of their own.
So, the leaves on the clover (Quadrifoglio) symbolize each of Alfa Romeo's original four drivers, Enzo Ferrari, Giuseppe Campari, Antonio Ascari, and Ugo Sivocci,.