Known as Series 2 (from chassis #1499GT). The main visual difference is the turn signal repeater moved from the rear pillar to the front wing. Technically, the main difference is the disc brakes instead of drum brakes.
The main differs from stock cars were: round repeater turn at the bottom of the wing instead of in drop-shaped on the top on a serial and a slightly different grille on the wing.
WheelsAge.org '2005–prés.