Audi wasn’t the only carmaker showing off an official tuner special at this week’s Wörthersee 2007 Auto Show. Sister brand Volkswagen has unveiled its hotted up Golf GTI W12 650 concept car, a race inspired hot hatch packing a Biturbo W12 engine developing peak power of 650hp (477kW) at 6,000rpm and torque of 750Nm.

That kind of output is good for a 3.7 second dash to 100km/h and a top speed of 325km/h. Its 6.0L Biturbo engine is positioned longitudinally behind the driver and front passenger seats and is mated to a six-speed auto driving the rear-wheels. A major technical problem was feeding the engine with enough air, so the lower c-pillars were designed in such a way as to direct air to the engine and the roof was fitted with a carbon-fiber diffuser.

The exterior has been modded with a full wide-bodykit, the GTI now measures 1.88m wide, and rides on super-wide 295mm rubber at the back. These tires had to be specially engineered to fit the unique light alloy wheels. Inside, there’s Alcantara and an assortment of new switchgear and gauges located behind the transparent flip-up switch guards.