It’s never too early to cash in on Christmas, so last week I was making my annual crash bash wallop DVD for your yuletide viewing pleasure. Mostly this has involved filling old cars with petrol and blowing them up and driving new cars round corners much too quickly, while shouting.

It was enormously good fun hurtling round RAF Benson’s perimeter road on someone else’s tyres using someone else’s insurance. But it was even more fun when the filming was over for the day and I was faced with a choice of what to take home. Let me give you some idea of the scale of the dilemma.

There was a Corvette, which is much, much better than you might think, a BMW M5, a Golf GTI, a Ferrari 612, a Maserati Quattroporte, a Ferrari F430, a 6 litre Vauxhall Monaro, a Mitsubishi Evo IX, a TVR Sagaris, an Aston Martin DB9 Volante, a Mitsubishi Evo VIII FQ-400, a Range Rover Sport, a Ferrari Enzo, a Porsche 911 Turbo and rather hopelessly, at the end of the line, a Vauxhall Astra.

All of them were full of fuel. All had their keys in the ignition. All were clean, insured and ready to go. And each night, for a whole week, I just had to choose.

For a blast round the airfield it’d be the Vauxhall Monaro, no question. That thing is a big old softy with the heart of an elephant and the rear end from a small hyperactive dog. But on the road, when you can’t smoke the tyres and hang the tail out some of the appeal is lost.

It’s the same story with the Corvette. And I’m afraid that after eight hours of shouting and blowing stuff up I wasn’t really in the mood for a supercar. That’s why, most of the time, I took the M5. But then, one day, the sun came out and I caught the DB9 Volante winking at me . . .

Now in hard-top form the DB9 is sublime, an intoxicating and irresistible mix of style, elegance, power, noise, majesty, tradition, comfort and practicality. So you’d assume that taking the roof off to create the Volante would add yet more strings to its already formidable bow.

This is not always the case, of course. A Ferrari, for instance, is pretty much ruined by the removal of its roof. And so’s a Porsche 911.

That’s because these cars are designed to be the absolute last word in driving pleasure. If you take away the roof some of the body’s integral strength is lost and if you replace that strength with underfloor beams and bars you add weight. So either way the point of the car is completely lost. When I see someone in a drop-top Ferrari or 911 I always point at them and laugh. Because going out in a convertible 360 is like going out in a superb pair of trousers with a wet spot at the front.

The Aston Martin DB9, however, is different because it was not designed to be the last word in driving pleasure. It was designed to be a comfortable, elegant and powerful long-distance cruiser, a GT car in the real sense of the word: a Grand Tourer.

So removing the roof, losing the structural integrity and adding weight is a small price to pay for all the DB9’s attributes . . . plus an al fresco helicopter hair-do. It shouldn’t really matter. And yet, I’m very sorry to report, it does.

First of all, and most seriously, some of the coupé’s looks are lost. It’s still a pretty car, make no mistake, but it doesn’t have that hand-biting Oh my God-ness of the coupé.

Without a roof you notice that the A-pillars are rather too vertical, and with nothing connecting the rear haunches to the windscreen it has the appearance, if you can imagine such a thing, of a lion that’s had its backbone amputated. It feels that way, too.

When you drive on a normal village street at normal village speeds you can actually feel the whole car flexing and the steering wheel shimmying in your hands. This so-called scuttle shake isn’t as bad as it was in, say, an early Saab convertible, or the old drop-top Escort XR3i. But it’s nowhere near as good as modern technology allows.

There’s more, too. Because the Americans will not buy a car of this type unless it has two back seats — no matter how small and useless they may be, and in the DB9 they’re very small and very useless indeed — the DB9 does not have a wind deflector behind your head. So on the motorway life in the cabin is breezy. At 186mph it would be intolerable.

Strangely, however, the Volante cannot do 186. The hard top can but the engineers were worried that if someone drove at such speeds with the hood in place the fabric might be damaged. So the Volante is electronically limited to 165.

I’m sorry. I thought this was the country that invented penicillin and steam power and the Spitfire. I thought this was the home of ingenuity and engineering panache. And yet here is Aston Martin telling us that while the Germans and Italians can design a hood to withstand speeds in excess of 165mph, we cannot. That’s not good enough, boys; not by a long way.

This is my big issue with the Volante. As you trundle along with the chassis flexing and too much wind in your hair and an electronically limited top speed, you can’t help wondering if this car was either rushed into production or done on the cheap, or both.

Take the buttons on the dash as another example. They’re beautiful, for sure, and when they’re shaded by a roof they work well. But with the sun glinting on the satin finish it is impossible to see which one does what. One of the test drivers must have noticed this when the car was developed. He must have wondered whether they could be changed. But they weren’t. And this in a car that costs £112,000, £9,000 more than the coupé.

Of course on smooth roads all is well. You still have the wonderful gearbox, a stereo that can easily compete with the wind noise and, best of all, the steering judder that plagued early coupés is now gone. If you’re not that interested in speed and delicacy and razor-sharp engineering I suppose it’s still a nice place to be.

But I am, so the Volante is a major disappointment. And interestingly my co-hosts on Top Gear arrived at exactly the same conclusion after testing the car elsewhere. It’s rare that we agree on . . . well anything, really, but we all came back from a drive in the drop-head DB and said the same thing. It’s a great car, spoilt.

The thing is, though, we also agreed that we wouldn’t laugh at anyone who bought one. Chiefly because, despite the flaws, this is still so cool that if you stuck a thermometer up its jacksie, the reading would be –274C. One below absolute zero.

It has the same appeal as a classic car. By today’s standards a Ferrari Daytona is not fast, not comfortable and has the handling zest of a JCB. In every measurable way, a modern Vauxhall Astra is better. But which would you have? And that’s the thing with the Volante. It’s not the best car in the world, not by a long way, but it is an Aston Martin convertible and that sort of makes it good enough.

That said, when the DVD shoot finished and I was faced with the choice of what car to take home for the whole weekend, I still went for the amazing M5.

Unfortunately, as I was leaving the airfield its transmission exploded, the rear wheels jammed and the on-board computer shut down the V10 in a big hurry. It ended up going back to its maker on a tow truck. I ended up going home in a rented Mondeo diesel.

It was better than the Aston and yet, of course, it just wasn’t.

Vital statistics

Model Aston Martin DB9 Volante
Engine 5935cc V12
Power 450bhp @ 6000rpm
Torque 420lb ft @ 5000rpm
Transmission Six-speed auto
Fuel 17.1mpg (combined cycle)
CO2 394g/km
Acceleration 0-60mph: 4.9sec
Top speed 165mph
Price £112,000
Verdict Flawed but still fabulous
Rating 3/5

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