Gents, I have a Maserati "Product Information & Pricing" book dated April 1st 2006 which clearly states it as a Maserati GranSport Spyder, discuss!. (If I had the technical ability I'd scan it and show you all!), ADG
From the Maserati web site...Clearly says Maserati 90th Anniversary Spyder.....and I quote..
'The more sporty look of the GranSport Spyder was anticipated by the adoption of new front and rear bumpers, together with more pronounced sill covers'
Maserati Spyder 90th Anniversary
2004 In 2004 Maserati celebrated the 90th Anniversary of the company's founding with a triple event organized in Italy and culminating in Rome, where some 300 Maseratis gathered together. As a further way of honoring the landmark a special limited-edition model of the Spyder was introduced, with production limited to just 90 units. It was officially presented in September 2004 at the Paris motor show, in the same month as the celebrations were taking place.
The more sporty look of the GranSport Spyder was anticipated by the adoption of new front and rear bumpers, together with more pronounced sill covers. This version of the Spyder also featured lightweight carbon-fiber rear roll-hoop fairings inlayed with attractive blue polyester strands embedded into the weave. Finished in either the exclusive Blu Anniversary livery or silver, the Spyder 90th Anniversary sported exclusive design features including distinctive oval Trident logos on the front wings, paying homage to the 250F driven by Fangio in the 1957 Formula 1 World Championship. Headlight cluster mountings were in contrasting grey, emphasizing the profile of the hood and chrome door handles, and ball-polished 19" rim wheels (with titanium colored brake calipers) and the classic red-striped Trident adorning the front grille completed the exterior look.
Blue carbon fiber was also present in the car's cockpit, enhancing the upper and lower sections of the center console and matching the blue and cream two-tone leather lining the seats, dashboard and door panels. The 90th Anniversary model featured a grouped centre console with blue-starter button and high-performance stereo system in place of the Maserati Info Center LCD display screen. A commemorative plaque on the lower console indicated each car's serial number.