James Bond may have toyed with a Toyota and gone submarining in a Lotus, but there's only one car worthy of the greatest spy of them all. As the new Aston Martin DBS makes its screen debut, Michael Booth explains why this is the car that fantasies are made of.

My therapist tells me that a fantasy life is a perfectly healthy thing for a well adjusted adult to indulge in from time to time. This is quite a relief. After all, who among us has not spent a few moments in happy reverie imagining we have won the lottery? And who among us hasn't insisted that their wife accompany them in an Aston Martin Vanquish to the Dungeness nuclear-power plant; that she address them as "James" throughout the journey; and then join in"pretending" that the power plant is a crazed megalomaniac's lair being used as a base to hold the world to ransom with some unspecified weapon of destruction; before flooring the accelerator amid a peal of tyre-screaming smoke as you attempt to flee before the timing device you have placed in the core reactor explodes while being shot at from a pursuit helicopter? I know I have.

Driving an Aston Martin, if only for a couple of days, can have this effect on a man. I have been lucky enough to drive a few over the years, so I wasn't surprised to hear that in order to prepare for the lead role in the new James Bond film, Casino Royale, Daniel Craig felt it was vital to spend some time at Gaydon, the company's HQ, driving Astons old and new. While there, Craig underwent high-speed driving instruction with Aston's chief test-driver, Les Goble, and went for a drive in a 1968 DB6 (the ex-Paul McCartney DB6 no less) to give him an idea of how a DBS - a close relative of the DB6 - would feel when he drove one on location in the Bahamas a couple of months later. For many actors it is the shoes or the fake nose that give them the searing insight into their character but it would seem that, if you are about to play the world's most famous secret agent, the key to the character is the car.

And what a car he's got this time; quite probably the best thus far in what is the longest-running movie franchise in history. The submarining Lotus was cool, of course, but, like its driver, Roger Moore, also a bit of a joke; Connery drove a Toyota in You Only Live Twice, and though that wasn't as bad as it sounds (it was a sublime 2000GT, with the roof chopped off especially to accommodate Connery's 6'2" frame), it still wasn't quite the right set of wheels for Her Majesty's secret agent. And I think we should all try to forget the unfortunate episodes with those product-placed BMWs during the Pierce Brosnan era (Bond in a Z3? What, next? Wearing a Hermès headscarf?). No, Bond must drive an Aston Martin and for Casino Royale he has been given what could well turn out to be most impressive Aston Martin ever made: the new DBS.

Aston had already begun work on the DBS before the £100m budget Casino Royale had been cast. Intended from the start to be Aston's new flagship model (though it is not, as widely reported, going to replace the Vanquish), the DBS is a kind of road going version of the DBRS9 racer. Exact details of its specification are still scarce, but we know it will have the 6.0 litre, V12 engine shared by the Vanquish and DB9, in this instance pumping out an estimated 530bhp. With a kerb weight reduced to around 1.5 tons through the use of carbon fibre for the doors, bonnet, boot lid and special racing seats, you can count on a top speed comfortably in excess of 200mph and 0-60mph in less than four seconds.

Aston supplied two fully functioning DBSs for the filming of Casino Royale - no mean feat considering the car isn't even scheduled to commence production until late next year.

Though the DBS existed in sketch and model form as long ago as October of last year - back when virtually every young, male, British actor seemed to be being mooted as the new Bond - Aston's head of design, Marek Reichman, claims that it wasn't until he actually met Craig that the car's true character began to form. This is, then, the first time an Aston has been unveiled in a Bond movie before ever reaching a motor show (in fact, it won't be officially unveiled until the Detroit show in January, and no orders are yet being taken for it). And it is perhaps the first time ever that a car has been directly inspired by an actor.