He's an outgoing, wisecracking sort of bloke, but you can see the suggestion irritates him, though he acknowledges that a company called David Brown Automotive has more instant gravitas today than a Trevor Smith Automotive would do. That much he knows he owes DB Mk1.

The Speedback idea sprang by degrees from the fun Brown has had over the years building wild rally cars, and entering both UK events and globetrotting productions like the Paris-Peking Rally (in a '20s Rolls-Royce).

Many years ago '60s-loving Brown bought an Aston DB5 and modernised it with more power, soundproofing and better brakes. "I love it, and still have it," he says, "but after all that it was still a '60s car. I kept wondering how I could have a modern car with the look I liked."

Under the skin the David Brown Speedback GT uses a Jaguar XKR chassis, engine and all its other significant mechanical components, but is carefully designed so virtually everything you see is unique.

The interior is a celebration of wood, leather and metal details. The exterior does plenty of DB5 details better than the old original (check the finely sculpted front bumperettes). As you would expect nothing is left to chance, with the Speedback GT capable of stowing 243 litres of luggage with the seats up and 502 litres if you lower the rear ones. The body is made of aluminium to increase structual strength and reduce the overall weight, while there are LED headlights, performance brakes, active differential and dynamics.

Inside there is a plush interior for occupants to enjoy, led by the wooden-rimmed steering wheel, dual-zone climate control, soft-close doors, automatic wipers, electrically folding door mirrors, parking sensors and reversing camera. Like any modern vehicle, dominating the centre console is a 7.0in touchscreen infotainment system complete with sat nav, Bluetooth, USB connectivity and a Bowers and Wilkins audio system.

However, one very special feature is a so-called picnic seat, an ingenious mechanism that springs from the flat boot floor. It's a two-person perch to please any SUV owner, except that this is a svelte GT car.

The Speedback's use of proven high-performance components recall days when those who could afford fine cars would buy a rolling chassis from the likes of Bentley or Alvis and have it fitted with a body of their own specification – perhaps with some personal design elements thrown in by their choice of coachbuilder, who at the time were dealers in exclusivity.

The Speedback's styling, inside and out, is the work of the well-known ex-Land Rover designer Alan Mobberley, who came out of retirement for this because he reckoned he was old enough to understand what made Astons of the DB5 era so special. "It's a contemporary GT with the heart and soul of a classic," he says.

For all the logic of coachbuilding for exclusive, expensive cars, Brown has already met criticism that his car is ‘only a Jaguar underneath’.

That's despite the fact that the Jaguar components are some of the best available, developed over at least half a dozen iterations by some of the world's best engineers. Jaguar itself seems happy with the idea, and the Speedback GT's concept seems splendidly at home with its dynamic bits.

That's something we pretty soon established on some of the finest roads of Yorkshire, many of them comprising the route recently traversed by the Tour de France.