F-Register's db shows #117904 being a late 1999-production 550 Maranello, but not a common or garden car, but another special one.
In 2000 this car was used as a Factory prototype called "Sperimentale" and the chassis was subsequently renumbered to 143658 in 2005! The "Sperimentale" would well fit the cars we previously covered in Michael Benner's Diaries. Those prototypes are always intended to check out enhancements or ideas that sometimes become part of the next generations' cars. With #117904 the Factory tried three different developments: first of all, the Factory tested the use of a side exhaust. 2000 was well the time when many car makers tried some retro elements on their newly introduced cars. To make the exhaust system fit to 117904's chassis, it was lengthened and became 10 % stiffer than a production chassis. The second test-feature was an air duct system that was installed for fuel cooling reasons. Third innovation was a system of moving pedals and a moving steering column to keep the ideal seat position of the driver.
The "Sperimentale" was offered as lot # 226 at the famous RM Auction "Ferrari - Legenda e Passione" held in May 2007 at the Circuito di Fiorano. It was hammered at 165,000 USD at the auction.
If you take a glimpse at official Japanese dealer Cornes' inventory, you will find S/N 117904 in there, but not, as many of us may expect- ZFFZR49B000117904 but as ZFFCZ56B000117904 - what makes it an Enzo!
We know that the first official Enzo is #128014 and we are not sure but we assume, that #128011 to #128013 belong to the regular "pre-production"-range of the Enzos. It is common knowledge today that there are more than the official 399 + 1 Enzos and that those post-production cars have been assigned very early Serial Numbers that in no way would fit the serial number range of Enzos. Beside the M1 and M3 prototype built on 348 chassis –including the guess that there might be a M2 as well-, there are at least ten early Serial Numbers between #103820 and #127766 that have been identified as Enzos. However, Cornes’ advert shows the so called matricola-plate wearing #117904!