David Brown Speedback GT, motoring review: Would this lithe and elegant car impress 007?

Price: £594,000
Engine: 5,000cc, V8, 32 valves, supercharger, 510bhp
Transmission: 6-speed automatic gearbox, rear-wheel drive
Performance: 155mph, 0-62 in 4.8sec, 23mpg, CO2 292g/km

'What is that?" You can see the words forming on people's lips as you drive past in this shapely grand tourer. It triggers a familiarity in the onlookers' minds, but it doesn't quite tally. An Aston Martin, perhaps? That's the usual best guess.

Given that this car's creator is called David Brown, as was the man behind all the DB-series Aston Martins (of which James Bond's DB5 is the most famous), the connection becomes almost irresistibly obvious. But there is none, apart from some influence in shape and style and the coincidence of the name.

What you're looking at is in fact a Speedback GT. Or rather the Speedback GT, because so far there is only one. The plan is to build around 100, some of them convertibles, and three more are currently under construction, with a further three due to start when the customers have finished choosing specifications. It is Brown's dream-made-real, conceived after a hot classic-car rally in southern Spain in which a hired Peugeot with air-conditioning found itself favoured over a glamorous old Ferrari with a driver-cooking cabin and progress-thwarting fuel vaporisation. A glamorous GT with retro appeal but a modern car's comforts and usability, that was the idea.

Designer Alan Mobberley, with 50 years in the industry and Jaguar and Land Rover on the CV, can't deny the Aston Martin influence. It's a retro-flavoured British GT, he points out, so it could hardly not have something of the look. But while it would just need an Aston front grille to be a complete pastiche, instead it has something slightly Maserati-flavoured.

Looking lithe and elegant, the car is based on the aluminium underpinnings of a Jaguar XKR, which is stripped of its outer panels and reclothed in a retro, but still aluminium, suit. The interior, too, is XKR-based but reshaped and retrimmed with new instrument faces and switchgear surfaces. The windows are unique to the Speedback, and opening the rear hatch reveals a floor panel which you lift up to create a fold-out, rearward-facing "picnic seat". The whole car is built in and around Coventry, outsourced to firms well versed in creating prototypes for major car-makers and aftermarket luxury conversions.

To drive the Speedback is to feel a soft collision of worlds old and new. The view forward through the shallow windscreen is of shapely front wings and the bonnet's air scoop. The surroundings are of rich leather, lavish but restrained wood veneer and polished metal. Rear-seat space might just be enough for a couple of under-eights. You'd expect the performance, handling characteristics and ride to mirror an XKR's, but they don't, quite. Certainly the pace from the 510bhp V8 is on full form, but softer, higher-profile tyres on wire-spoked wheels soften the dynamics. The Speedback actually rides better than an XKR and feels calmer, to the benefit of its grand-tourer role. You can cruise gently without feeling you're wasting the car's potential, yet it will let rip if asked. It's all very pleasant.

There's just one snag: a car as expensively hand-built as this can never be cheap to buy. It costs £594,000, which would buy you eight-and-a-half XKRs. But in the strange stratosphere of luxury brands, a huge price tag can just make an object more desirable. David Brown hopes so, anyway.