An evolution of the previous 350 GT, Lamborghini's 400 GT arrived on the market in 1966. This car featured a larger (4L) V12 engine as well as design adjustments and cosmetic changes to the interior. During the transition from the 350 GT to the 400 GT, a limited run of twenty-three 400 GTs was made featuring a 350 GT body, but with the updated 4L V12. These so called "interim" cars are a rare find on the market. After the 400 GT "Interim", the updated 400 GT 2+2 body entered production, with the most noticeable change being the addition of two rear seats, giving these cars their "2+2" moniker. As well as rear seats and cosmetic tweaks, the "2+2" model featured a new gearbox that greatly improved driveability.