Lamborghini had presented an open-topped concept version of the VT (Viscous Traction) at the 1992 Geneva Auto Show alongside the coupé when the car debuted there, but it was another 3 years before the model saw production. Other than its removable Targa-style carbon fiber roof panel, the vehicle was essentially identical to the coupé, with only a few minor styling differences, mainly in regards to the tail lights between the two models. The SV or "Sport Veloce" variant of the Diablo was an optional add-on package to the base car. It lacked the VT's all-wheel-drive system and electronic suspension, but it featured the VT's revised dashboard and larger brakes, a new 3-piece adjustable spoiler and was powered by a modified version of the 5.7-litre V12 producing 510 hp (380 kW). The car's air intakes were slightly differently shaped, and from 1999 onwards the vehicle had exposed headlamps as opposed to the pop-up units previous versions used.
After Audi AG took over Lamborghini from its former South East Asian owners in 1998, Mycom and VPower, they set out to make major revisions to the Diablo so that it could continue to provide revenue while its replacement was developed. The VT 6.0 was their first (and last) truly intensive redesign of the car, meaning that it was more than just a cosmetic update to the existing model. Heavy styling changes both inside and out were made; the front bumper, air intakes and nose as well as the entire dashboard, seats and switchgear were changed and improved. Displacing 6.0 litres and based on the motor that powered the Diablo GT, which in itself was essentially a modified version of the 5.7, the motor had updated ECU software in addition to new intake and exhaust systems and a refined variable valve timing system with slightly less aggressive camshafts than had been used in the earlier versions.Source: Wikipedia.