Blazing performance from the Aston Martin Rapide

Kevin Hackett discovers that the Aston Martin Rapide, the four-door hatchback version of the DB9, can really take the heat.

The Aston Martin Rapide, "the most beautiful four-door car in the world", performed brilliantly during testing under extremely harsh desert conditions in Kuwait.

Being a Brit obviously makes me mildly obsessed with the weather, yet whatever complaints I have about the climate of my own country, I've never wanted it to be 51°C. In the shade. Yet the car's exterior-temperature gauge is telling me that's exactly what it is. Taking leave of my senses, I decide that this incendiary heat is something I want to experience first hand, so I open the car door and leave its air-conditioned, leather-lined cocoon of an interior to face the fierceness of this featureless landscape.

This is the Kuwaiti desert, and I've never before felt heat like it. My eyelids are ready to combust; it actually hurts my lungs more with each breath drawn. The wind really whips up and clouds of sand are swept across the near-melting road surface. It's quite beautiful, the way it dances around, but its effect on my face is excruciating as my skin is unceremoniously sandblasted. Much more of this and my cheek bones will see daylight. Time to get back in the car, and I can't pretend that's much of a chore, really.

Getting into an Aston Martin is never a chore. The way such ethereal beauty can clothe such savage power makes grown men weak at the knees and this one, the four-door Rapide, is possibly the company's most important model in its long, varied history. It is, according to Aston Martin, a DB9 without compromise. In other words, with the Rapide you'll be able to share the magic with three, normally limbed adults. Having ferried my teenage son to school in a DB9 with two of his mates squashed in the back, knees around their ears, this seems like a properly good idea, on paper at least.

And the four-door sports car has recently come of age, with offerings from Maserati and Porsche, with even Lamborghini getting in on the act with its Estoque concept car. So there's a lot resting on the shoulders of Rapide - it needs to be very good indeed. I'm accompanying Simon Barnes, Aston Martin's vehicle engineering manager, and we're on the 50 Highway, not far from the Saudi border, putting it through the final stages of hot weather testing. He's the guy who decides how this car will ride, drive and sound; if he doesn't like something it won't end up on the production car, it's as simple as that.

This is one of just 14 prototypes. There are imperfect panel gaps here and there, belying its test car status, door seals are temporary and the interior is only partly finished, with cables everywhere feeding information from dozens of sensors to the computers and data-loggers in the boot. As we take shelter inside the car while the sandstorm lashes around outside, I have to ask: why Kuwait? I know Aston Martin is half owned by the Investment Dar in this country, but couldn't these extremes be replicated in some chamber back at the UK factory?

"There's more to hot weather testing than ambient temperatures," says Barnes. "For instance, the driving standards in Kuwait are appalling. Cars here are driven bumper-to-bumper, which puts more pressure on the cooling system as less air is directed into the front of the car. There are so many variables that only testing in real-world conditions like this will do." The desert causes its own set of problems, too. The airborne sand etches headlamp and windscreen glass, causing much premature damage. Air filters need emptying daily and the heat puts a massive strain on all the electrical items. "Many of our customers will be based in the Middle East," says Barnes, "and we need to be absolutely certain that our cars will be reliable. There's only one way to do that and that's why we're right here, right now."

Barnes puts the car through its paces on one of the most desolate roads I've ever seen. From standing, with four adults inside, the car rockets to 160kph in barely a few seconds, and then he's back on the anchors, stopping it dead in its tracks. We do mile after punishing mile in temperatures normally associated with Death Valley, and it's clear there's no doubting the Rapide's sporting personality. It feels indecently quick and as nimble as the diminutive V8 Vantage, thanks to its extensive development programme at the infamous Nürburgring, where Aston Martin has its own research centre.

Once we have had enough of the relentless heat and wind, we head back to Kuwait City and drive through the maze of streets to the iconic Kuwait Towers. Barnes was right - the driving here is astonishingly bad, and the stop-start-stop traffic would have seen a 1980s Aston stranded on the side of the highway with steam pouring from every orifice. Other road users stop dead in their tracks, spellbound by the Rapide's glamorous good looks. Camera phones are pointed at us and, within a few hours, we're stars on YouTube. The appreciation of beauty evidently knows no national borders.

The rear quarters of the Rapide are snug, yet there's room for even 6-foot-2 Barnes to get comfortable. Two individual seats are divided by a substantial centre console that houses controls for the DVD player (screens are in the headrests of the front two seats) as well as the vents for the rear's individual climate control. Getting in and out isn't as easy as it might be with the rear doors of a Jaguar XJ or even a Maserati Quattroporte, but that doesn't cross your mind once you catch the car's reflection in a shop window.

Aston's design director, Marek Reichman, and his small team have managed to turn the physically flawless DB9 into a four-door hatchback and make it look as though it was always supposed to be thus. There are only minute detail differences between the car I am in today and the design study concept that stunned everyone in 2007, and every body panel is unique to the Rapide. "We wanted to make the most beautiful four-door car in the world," Reichman said at the time. Mission accomplished. There are newly-shaped headlamps hinting at the future evolution of existing models, and the company's unmistakable side strake has been extended along the front doors and into the rears. Both sets of "swan wing" doors move upwards as they open outwards as per the rest of the range. The DB9's 6.0L V12 engine has been pressed into active service up front, meaning there will be 470hp on tap and a (yet to be confirmed) top speed of 305kph.

There's good news, too, for front-seat occupants, as there's a revised cup holder design, neater switchgear and the addition of an electronic parking brake to replace the infuriating item that blights the current crop of Astons. This change alone has made for greater interior space by allowing larger seats to be positioned closer to the Rapide's extremities. Even as a passenger, I can feel that the Rapide bears all the characteristics of the DB9: massive reserves of riotous V12 power and just the right balance of personality and refinement. It's a bit quiet for my liking but, according to Barnes, that's something yet to be dealt with. "It's much easier to make a car quiet and then dial in the noise later," he promises with a wry grin. When Porsche's engineers get ahold of this, they just might understand what the Panamera could have, should have been. But then again, probably not.

Not only is the Rapide a first for Aston in that it has four doors but it will be the first model not assembled in the UK, as there's simply no way the factory at Gaydon could cope with the extra demand. Instead, there is a dedicated assembly line being finalised at independent car producer Magna Steyr in Austria, where Mercedes and BMW already have some of their models built. But wherever this beautiful and surprisingly versatile car is assembled, the fact is that (unlike this particular Brit) it's Kuwait-proof. And that's as good a recommendation as any. [e-mail]