Not happy with life on screen, Citroën turned the virtual GT into carbon fibre-bodied reality, thereby providing a vivid demonstration of its commitment to the kind of innovative design for which it was once famous. When it arrived at Goodwood for last year's Festival of Speed, however, the GT failed to take to the hill as planned on account of - you've guessed it - a broken clutch.  In 2010 things would be different. That clutch has been upgraded to a twin-plate setup and the GT is once again mingling with the Bugattis, Ferraris and Lamborghinis, among which its pearlescent white body looks impossibly low, long and wide, like a sci-fi intruder has landed in the supercar paddock.  I slip into the driver's seat while alongside me Citroën's Patrick Arnaud assumes the role of passenger/supervisor. He's terrific company, brimming with enthusiasm for his job running the firm's concept car programme and speaking in a thick French accent as he describes the GT. "She is very eavy to drive," he warns, "and very ot." I'm told to also ensure that there are no babies around before I rev the engine, just in case the noise - which is utterly explosive in volume - damages their hearing. I'm pretty sure he was being serious, too.  Oh yes, the engine. Its identity is a closely guarded secret within Citroën but it sounds every snarl and pop like a big, unsilenced American V8. From inside the cockpit, which is lined with great swathes of copper and boasts a Formula One style steering wheel, I note that Arnaud's comments about the heat are justified: by the time I've made my way to the start line, blasted off (mercifully without stalling) and wrestled the GT's heavy steering wheel into the first turn there's no way to hide the sweat breaking out across my forehead.  Sensing the crowd's anticipation I squeeze the throttle open as we pass the house before having to jump hard on the brake pedal in preparation for the course's trickiest turn, Molecomb. The GT's mid-engine layout convinces me it's best to drive in a manner that will promote as much stability as possible, braking in a straight-line and powering through corners. True to form for a concept car its suspension feels far from a finalised setup, sending uncomfortable crashes through the cabin on more than one occasion.  As for power, something around the 500bhp mark feels viable. The gearbox is a six-speed manual operated via buttons on the wheel. I don't get above fourth on the 1.16-mile climb but with high speed behaviour a complete unknown it seems that a combination of low gears and lots of noise is my best chance of pleasing the crowd.  Aside from the noise, the heat and the physical effort involved in actually getting the thing around corners, the sensation that strikes me most is just how wide the GT is. A seating position that puts you just millimetres from the tarmac also makes judging the car's extremities tricky, while rearward visibility is non-existent (those wing mirrors are, like many elements of the GT, an exercise in form over function).  By the time we squeeze through the finishing posts at the top of the hill I note that my passenger has fallen silent. I assume he's either happy, terrified or has passed out from the heat. I make a judicious stab at the throttle, just to check he’s still with us. Sure enough, as the GT barks I catch Arnaud smiling. Perhaps he’s just realised that in a field of the world’s most exclusive supercars his Citroën is stealing the show.
Driving Citro&euml;n's &pound;1 million GT concept car up the Goodwood Hill at this   year's Festival of Speed.