For 1999, Ferrari introduced a limited production of F355 Spider models designated, "Serie Fiorano" Launched in March, 1999, this limited production run of 100 planned units (104 actually produced) included a number of enhancements increasing the race track performance much closer to the Challenge versions.
There were 100 Serie Fiorano units delivered to the U.S. market, 74 with the F1 transmission and 26 with the 6-speed manual. An additional 4 units were produced beyond the planned production for the U.S., with only 3 European models and one South African delivery. The American units were delivered with a numbered plaque affixed to the dashboard. The 3 Fioranos delivered to Europe had no numbered plaque affixed to the dashboard.
Source: Wikipedia (original)