Probably the most fascinating car for Italian automotive enthusiasts' to take to the track at the weekend's SpaItalia extravaganza was the ultra-rare Lamborghini Diablo based Pregunta concept supercar built by automotive industry player Heuliez, and which was first shown a decade ago at the Paris Mondial de l'Automobile.

Probably the most fascinating car for Italian automotive enthusiasts' to take to the track at the weekend's SpaItalia extravaganza was the ultra-rare Lamborghini Diablo based Pregunta concept supercar built by automotive industry player Heuliez, and which was first shown a decade ago at the Paris Mondial de l'Automobile.

Pregunta is drawn from Spanish and means 'question' and the name summed up the aims of this project, where French automotive contractor Heuliez was posing a big question to the rest of the industry. Ten years ago Heuliez, which had previously carried out some specialist niche model conversions for Citroën and assembled a handful GpB rally cars for Peugeot, was aiming to expand internationally and bid for greater recognition.

So Heuliez initiated a bold project to build a supercar prototype that would grab the world's attention and showcase its ability to build a complete working car, rather than just a show special. Heuliez' Turin division reached an agreement with Lamborghini to develop the project on one of its chassis, and the whole project was led by designer Marc Deschamps.

Built during 1998 the Pregunta has a tubular alloy frame and is based on a Diablo chassis. Heuliez left the 5.7-litre V12 engine and mechanicals untouched however; it weighs 1650 kg and sits on OZ alloy wheels. With 530 bhp on tap the Pregunta had a claimed top speed of 333 km/h and a 0-100 km/h time of 4 seconds.

Its aggressive and unusual styling give the car a strong and unique identity, the aim was to mix a blend of an aerodynamic and uncompromising race car with hints of a fighter plane. Inside, the Heuilez team paid great attention to creating a cockpit that continued to bring the racing car experience to the driver, and at the same time offer much comfort to the passenger, while the aerodynamic theme of the exterior can be clearly seen to have been carefully continued inside. The Pregunta showcases much advanced technology of the era, utilising an F1-style LCD display dashboard developed by Magneti Marelli, along with a Cristine navigational control unit (BCI), CD radio/stereo (Alpine), multi-seat harness belts (Schrott) and fibre-optic lighting cables (DGA) which wrap themselves around the cockpit.

Having made an impact on its world debut on the Heuliez stand in Paris ten years ago, it also was shown in Geneva the next spring. It then vanished from sight before reappearing at the Retromobile classic in Paris last year. At Spa over the weekend the Diablo Pregunta formed the centrepiece of a display of historic Lamborghinis brought together especially as SpaItalia featured the Raging Bull marque; it also took to the track during the 'parade' sessions where it was put through its paces.