a wild guess could be s/n 139744, a FXX that was a prototype and a Muletto for the MC12 Matthias www.vinbook.com
That seems pretty clear giving that the regular MC12/MCC car is the same color and PIRELLI logos on the car.... BAR
check out maserati mc12 pics thread (page 11ish) after the filming when he hits it, the car came in to dick lovett ferrari/maserati swindon uk for a new clutch, ive posted some pics i took as i did the job. cheers