I always envied people driving around in their cabriolets, roof down, wind in their hair, sun on their backs, that is until I drove a drop top and my opinion changed rather rapidly. It was the noise, you see. If it wasn’t the wind, it the constant roar of other cars’ tyres on the tarmac, or heavy diesels chattering away over your shoulder when you’re sitting in traffic.

And so it was that the next time I was scheduled to review a cabriolet, my mind was already filled with negative thoughts, and regardless of the weather, I would keep the roof-down motoring to a minimum.

However, something strange, something magical, something unexpected happened during my week with what was, as if some part of a weird conspiracy, the little brother (the A3) of the car I’m reviewing here, the S5: My mind was changed again.

So I have high expectations of the S5 Cabriolet. Not only am I expecting it to be blindingly quick, but also quiet, comfortable and refined, whether the roof is up, or down.

The latest generation A5, and consequently the S5, is based on the new A4, so it shares Audi’s MLB Evo platform. It’s steel and aluminium construction allowed for a reduction in kerb weight in spite of the new car’s marginal increase in size.

The S5’s track is wider than standard A5s, hence the need for the extended wheel arches that, in combination with the lowered ride height, give the S5 a squat, broad and athletic stance.

The singe-frame front grille is flatter and wider, and the addition of intakes and quad exhausts helps send out a clear message of intent but, despite what is, in reality a quite extensive overhaul, there’s no mistaking the S5’s lineage.

Audi has a justified reputation for bolting together some of the finest interiors and the S5 continues that tradition with aplomb. Nappa leather upholstery, contrast stitching and Super Sports, logo-embossed seats are standard in the S5, providing a subtle but welcome upgrade over its less salubrious siblings.

There’s a consistency of tactile finesse throughout the cabin that other manufacturers, whether by design or default, struggle to match. It’s that unerring ability to hit the very highest mark time after time, to literally turn less into more, that makes climbing into every Audi such a universally pleasant experience.

Mounted on the dashboard is an 8.3-inch LCD display. I was disappointed to discover that it doesn’t retract into the dashboard and, as if often the case, I can’t help but think that, mounted as it is, it does rather look like a bit of an afterthought.

You can opt for Audi’s excellent Virtual Cockpit, which replaces the traditional instruments with a 12.3-inch TFT display. By default two digital gauges dominate the screen, while sandwiched between them is other, driver-selected, information such as audio playback, car systems and navigation maps.

What makes it particularly effective, however, is the option to minimise the dials. Simply press the View button on the steering wheel and those gauges shrink down to about a third of their original size, liberating a vast amount of space to display the sat nav maps in all their crisp, detailed glory.

At just £250 (or £750 as part of the Light and Vision pack) it’s hard to imagine why anyone spending north of £47,000 on an S5 wouldn’t opt for the Virtual Cockpit but, in doing so, it renders the central display largely redundant.

Operating the multi-media system is as simple as ever with Audi’s MMI interface – a rotary, touch-sensitive controller plus a smattering of shortcut buttons – which affords you with any number of methods of interaction.

If you don’t want to take your hands off the wheel, you can always use the excellent voice recognition to enter an address. It’s effective, but does require you to be quite specific about the order in which you speak the address details.

Investing another £750 - I know, it quickly adds up – in the Bang & Olufsen 3D audio system is a sound, ahem, choice if you’re planning on listening to Radio 4 with the roof down. The clarity and power make it a worthwhile, if not essential, addition.

There are rear seats but, despite a marginal gain in size, their use will be limited unless you’ve got either a young family or small friends. Or possibly both. Anyone of above average height won’t thank you for being cooped up in the back for prolonged periods but you’re unlikely to find better elsewhere in the segment.

Removing the great slab of metalwork that was the roof inevitably adds weight to a car in the form of structural reinforcement and the S5 is no different. That additional mass makes its presence felt during the 0-62mph sprint which, at 5.1 seconds, is four tenths slower that the coupe.

Not that it’s a slouch, by any stretch of the imagination and, for anyone who wants something with a little more clout, more of a white-knuckle ride, there’s always the RS model.

The S5, meanwhile, brings a touch of civility to proceedings. It always feels every inch the gentleman in the way that it delivers its power, as if its primary concern is always your comfort and wellbeing.

Consequently, the whole process can feel a little underwhelming, a sensation that the rather muted, soundtrack does little to alleviate, despite the occasional pops and bangs on overrun. It’s misleading though, because the S5 is a very quick car, but it provides all that power and pace in an easily accessible way.

Negotiate urban areas and the S5’s character starts to make sense. The engine burbles along almost silently, while the silky smooth eight-speed gearbox is the epitome of subtlety and precision.

To compensate for the additional mass the suspension has been softened slightly in order to keep the inevitable shimmies that plague convertibles to varying degrees at a minimum. The ride remains on the firm side, and the reduction in stiffness does allow a little more body roll, but there’s a welcome degree of quiet compliance on broken surfaces.

You can, of course, tighten things up considerably with Audi’s Drive Select and, indeed, swapping into Dynamic mode results in a noticeable reduction in body roll and a much more planted, stable platform but there remains a disconnect between driver and tarmac.

There’s more than enough grip but the lack of feedback limits your ability to utilise it fully. Apply too much power on the way out of a bend and the nose will start to push wide but more judicious throttle control will allow the front end to stay nicely tucked in, following the trajectory established on turn-in.

The optional dynamic steering uses a superposition gear to vary its ratio by up to 100 per cent, depending on the car’s speed and the mode selected in the Audi drive select driving dynamics system. Its trouble is that, as a driver aid, it should be intuitive and, more crucially, invisible. It isn’t however, with a tangible and troubling tendency to over-assist through lower-speed corners while there’s a real sense of a lack of consistency, meaning that you’re often, even with experience, second-guessing the precise amount of lock required.

Judged purely on its driving dynamics, the S5 could be considered to fall a little shy of expectations, but few, if any, potential buyers will base their purchase on that single factor. To do so would be not only foolish, but also mistaken.

The S5 performs the sporting half of its remit with admirable effort and, though there are elements, such as the numb steering, that detract from the overall experience, it can be effortlessly quick whatever your driving habitat. What really stands out is its ability to be both quick, yet remarkably and effortlessly useable.

It is that sheer breadth of talent that makes the S5 Cabriolet such an irresistible proposition.

S5 Cabriolet Quattro 354PS Tiptronic

Price: £50,350

As tested: £61,230

Engine: 3.0-litre V6 turbocharged

Transmission: 8-speed automatic

Max power: 354PS

Max torque: 500Nm @1,370rpm

Max speed: 155mph

Acceleration (0-62mph): 5.1sec

Urban: 27.4mpg

Extra urban: 44.1mpg

Combined: 36.1mpg

Emissions: 177g/km

For more information visit www.audi.co.uk