Forty years ago Lamborghini produced a car called the Miura. For the first time a supercar’s engine was mounted directly behind the driver and slung transversely across rather than longitudinally along the engine bay. Knee-wiltingly beautiful, it was the car that was going to change everything. It made Ferrari look obsolete.

Except it didn’t quite happen that way. Ferrari went from strength to strength while Lamborghini struggled from owner to owner. Ferraris flew out of the showrooms by the thousand while Lamborghinis trickled out by the dozen, usually to stop not far up the road in a cloud of smoke.

Somehow, however, the company continued and in 1998 Lamborghini was bought by Volkswagen, to be run by Audi. The future looked bright to anyone who could see the promise of a car built using Italian supercar theory and German production car practice.

But when in 2004 I drove the car intended to finally deliver on the promise Lamborghini had made so many years earlier, I was disappointed. The Gallardo was quick but clinical, offered no challenge and had little character.

Now it seems Lamborghini was only practising. Anyone who remembers the head-to-head comparison with the Ferrari F430 in Driving nine weeks ago will know that the Gallardo has been transformed for 2006, and now they’ve gone and chopped its head off, too.

Dismiss this Gallardo Spyder as a poseur’s delight at your peril. Fabric roof or not, this car will reach 62mph from rest in 4.3sec and not stop until 196mph, or 192mph if you are sufficiently certifiable to have the roof down at the time. All the modifications that turned the Gallardo coupé from a pretender to Ferrari’s crown to a real challenger are present in the Spyder. There’s a 520bhp engine, shorter gear ratios, quicker steering and revised suspension too.

And there’s a beautifully engineered roof that can disappear beneath the carbon fibre engine cover within 20 seconds. Best of all, with the roof down there’s nothing to impede the engine’s assault on your ears. Thanks to its V10 formation, it sounds like a modern Formula One engine that’s been sampled, dropped a couple of octaves and blasted back with the volume at 11. You may think it’s a good-looking car but it’s a Trabant on bricks compared with the beauty of its sound.

Nor does this soundtrack promise anything the car cannot deliver. Explosive performance is matched by brakes strong enough to threaten to knock the air out of your chest.

There are acres of grip but when the car does start to slide it does so with an ease and progression rare in any supercar, let alone one with a mid-engined configuration. There are hatchbacks that are harder to drive really fast than this. Which, in another car, might make it boring. I have always enjoyed a good scrap with the various Lambos I’ve driven over the years, but you can’t fight this car because it makes it clear from the outset that it’s on your side. You understand that neither of you is master or servant: you’re in it together.

When you’re done having fun, you do that other thing this car was born for: posing. I always feel a fraud driving cars in glam locations when I can afford neither, but rarely more so than when wandering through the Florida Keys with a sunburnt scalp and a convertible Lamborghini.

This car will do good business everywhere it is sold. It is a Lamborghini to own, not simply to drive, a great-looking convertible with the reliability of an Audi that nevertheless retains the red-blooded passion of the traditional Italian supercar.

Back in 1966 it appeared Lamborghini was going to change everything. If this Gallardo is indicative of what’s to come from Lamborghini, then 40 years on it just might do that.

VITAL STATISTICS

Model Lamborghini Gallardo Spyder
Engine type 4961cc, V10
Power/Torque 520bhp @ 8000rpm / 376 lb ft @ 4500rpm
Transmission Six-speed manual
Fuel/CO2 Figures not available
Performance 0-62mph: 4.3sec / Top speed: 196mph
Price £115,000
Verdict Utterly convincing in every respect
Rating 5/5

THE OPPOSITION

Model Ferrari F430 Spider £127,050
For Mesmeric engine, superb handling
Against Looks slightly awkward, long waiting list

Model Aston Martin DB9 Volante £115,850
For Wonderful looks, smooth V12 engine
Against James Bond image wearing thin