The XJ-S was re-engineered in 1991 and renamed XJS, with a convertible waiting one year. The rear windows were enlarged, though the flying buttresses stayed, as designer Geoff Lawson argued that they were part of the car's character. The car got a new 4-litre version of the AJ6, and the V12 was upped to 6 litres in 1993/1994 (227 kW (304 hp)). At the same time the car benefited from a revision to the rear brakes, they were now fitted with outboard rear disc brakes, instead of the more complicated inboard items on previous models. With the introduction of the 6.0L V12, the transmission was also updated to a GM 4L80E with a 4th gear overdrive. These changes begin the "face-lift" for the aging XJS. A 2+2 convertible was also introduced, as was a customized insignia line. In 1994 the car received more aerodynamic front and rear bumper fascias, which completed the face-lift. 1994 was the only year the 6 cylinder with 5 speed manual transmission XJS was exported to the United States. Exact production figures are unknown, though it is likely there are fewer than 10. In 1995 substantial revisions were made to the 4-litre AJ6 engine which became the 4.0L AJ16 with coil on plug ignition being the most noticeable change. The car was discontinued in 1996, after 21 years in production. It was replaced by the XK8.