Which, for the engineers, must be a bit deflating. You see, despite the findings, the Germans have done a typically thorough job on the Cabriolet, giving it class-leading structural stiffness in a bid to put the driving experience on a par with the BMW 3-series Convertible.

Owners of the previous Cabriolet (72,000 of which were sold worldwide between 1991 and 2000) will probably notice the quantum leap in refinement and interior aesthetics. But it's unlikely they'll appreciate the savings in unsprung weight with extensive use of aluminium suspension components nor the 20mm reduction in ride height designed to lower the centre of gravity and improve steering response. So it only seems right that we put the A4 Cabriolet through its paces on the sun-scorched roads of Tenerife to give some feedback - for the sake of the over-worked engineers if nothing else. When it's launched this summer, the Cabriolet will be offered with 2.4 and 3-litre V6 engines - both front-wheel-drive; quattro models come later - and we've secured a 3.0 hooked up to a five-speed manual.

Approaching the car you can't help but be impressed. Both front and rear have been subject to a restyle to differentiate the car from its saloon sibling and it's a cohesive, well-resolved design. The nose-job gives the Cabriolet a distinctly TT-esque look and the overall effect is that of a stylish drop-top coupe rather than a chopped-down saloon.

Inside, the classy A4 cabin has been freshened-up with round air-vents and a unique centre console. Material quality is typically excellent and the hood is beautifully executed. When up, it does a great impression of a hardtop and has none of the pram-like ridges that affect the 3-series. At the touch of a button it retracts in less than 30 seconds too.

Firing up the Cabriolet is another treat. We're so used to the ubiquitous VAG 1.8 turbo engine that to be greeted by a tuneful V6 really gets things off to a fine start. For the feelgood effect that the Cabrio hopes to impart, the V6 is the perfect engine. Creamy, flexible and deliciously expensive-sounding.

In 3-litre guise it produces 220bhp and an impressive 243lb ft at 3200rpm, enough to give the 1580kg Cabriolet a decent turn of speed. The 0-60 is dispatched in around 7.5 seconds and the Cabriolet will hit 151mph thanks to its superb 0.30 drag coefficient (0.33 Cd with hood down). It never feels especially fast but the torquey nature of the engine allied to its enthusiasm for spinning out to the red-line means you're unlikely to crave heaps more power. Besides, it's not as though the chassis is crying out for more - to be truthful, this isn't the best sorted of recent Audis.

There's nothing wrong with the ride or the stiffness of the shell. In fact in these areas it excels. Even over the rare stretches of badly broken Tenerife tarmac the body never gets a case of the shakes. But throw a few tight turns and some committed cornering into the equation and the Cabriolet comes over all whale-like. The steering is typically Audi - stodgy and lifeless - and the chassis has only one party trick; terminal understeer. Now, we're used to Audis being set-up conservatively but the A4 saloon does corner with plenty of grip and a pleasing economy of line. On this evidence, the Cabriolet can't match it.

An uncomfortable lurching movement, loading up the front tyres but unloading the rears, mars turn-in. The result is a clumsy, disjointed approach to cornering. Big understeer on entry is followed by a momentary unsticking of the rear and a tendency for the front wheels to spin vigorously at the exit. Best to slow down and enjoy that mellifluous engine, beautifully wrought interior and the buffet-free open-top experience.

Which of course is what anyone who buys an A4 Cabriolet will do. Audi will sell every Cabriolet it can make because it looks fabulous, is cheaper than both BMW's 330Ci Convertible and Mercedes' CLK 320, and is likely to hold its value better than either.

The only worry is that despite a sophisticated suspension set-up, Audi still struggles to deliver a genuine driver's car. Hopefully the upcoming RS6 will restore our faith in Audi's ability to entertain - and some chassis magic will filter down to the rest of the range.