The N400 featured a few tweaks over the standard car. This included a useful power upgrade to the 4.3 litre V8 engine, lifting peak power to 400 bhp and peak torque to 420 Nm. The car also came equipped with a new Sports Pack as standard which offered subtly different driving dynamics tailored to enthusiasts who were seeking even more responsive handling. The Sports Pack comprised of unique lightweight graphite-finished aluminium wheel type with diamond turning (already fitted to the Sports Pack DB9), with up-rated springs and dampers. The N400 also included a number of exterior design changes, including a revised side sill design, Magnum Silver bonnet and side strake meshes, clear rear lamp lenses and a bright finish grille.
Interior enhancements included perforated black leather seats, micro-spin alloy facia trim and a unique numbered sill plaque. The N400 was only available in three new exterior colours; Bergwerk Black, Lightning Silver or Karussell Orange (the first time that orange has been a standard colour for an Aston I believe), with either Sportshift or conventional manual transmission. Additionally, the N400 came equipped with a range of optional equipment fitted as standard, including Satellite Navigation, 700W Aston Martin Premium Audio System, Bluetooth telephone preparation, HID headlamps, cruise control and memory/heated seats. In the Karussell Orange car, the seat stitching was course orange and a map of the Nürburgring was embroidered on the arm rest, the black and silver cars in course silver or sometime red or even black thread.
AML intended limiting production of the N400 to just 480 examples (240 coupes, 240 Roadsters) – why 480? well that’s how many seconds are in 8 minutes, the time that the N400 could lap the Nürburgring. Almost all cars were built during March and April 2008. It is now believed that somewhat fewer cars were actually built making the N400 especially desirable to collectors.