Rolls-Royce borrowed a London Bankside apartment for a preview of its new Dawn drophead. Ten floors up, with views directly across the Tate Modern and beyond, this split-level pied à terre de luxe conjured images of Spooks, 007, or other glossy dramatisations of contemporary London.

Nice: £7.5m of nice, in fact.

It was an astute piece of location scouting. Rather than a cigar-wreathed Mayfair gentleman's club, this is how the new generation of high-net-worth individuals live these days. (There was a Brabus G-Wagen 6x6 parked outside, whose owner apparently receives a fresh parking ticket every day because the thing doesn't fit in the space properly. First World problems, huh?)

So don't be fooled into thinking the Dawn is merely a roofless Wraith. It signals – sorry – the dawn of a subtly shifting era for Rolls-Royce.

Almost 70 per cent of its body panels are new, and it has a taut modernity in the flesh that puts more distance than ever between where Rolls – one of the world's most venerable car companies – has been and where it's going next.

Silicon Valley is shaping R-R's destiny as much as the House of Lords.

True, the name draws inspiration from the Silver Dawn, a flamboyant post-war sigh of relief that the world could put the deprivations of wartime behind it and party again. Well, the ones who didn't need to worry about ration books, anyway. A mere 28 were made between 1948 and 1952, the last Rolls to be custom-built by the coachbuilders who bodied Rollers every which way according to client whim.

But while the new car echoes the original's sense of dolce vita, it's got a new remit. It's a leaner, tougher, younger car.

"We love the '52 Silver Dawn," director of design Giles Taylor tells TopGear, "but it has a certain femininity that's not appropriate for the new car. If you look at the angle of the windscreen, and the way it flows into the hood, you can see that the formality has been relaxed a bit."

He's not wrong. Unlike virtually every convertible in history, the Dawn actually looks better with the roof up. Its glass area is actually quite tight, the windscreen aggressively raked, and the net effect is akin to a 21st century revamp of the sort of thing Jay Gatsby or Al Capone might have smoked around in.

Its body surfaces are all taut and meticulously chamfered, and although it shares the Wraith's wheelbase it looks smaller and punchier overall without losing the essential elegance that is core to Rolls-Royce.

The rear window is also surprisingly shallow, emphasising the neo-hot rod effect, the purpose being to reinforce arguably one of the most desirable of all modern commodities: privacy. Even with the roof down, all four occupants are well concealed although scarcely inconspicuous.

The preview car's 'midnight sapphire' paint finish is offset slightly by a strong coachline, and a lot by the 'mandarin orange' leather of the interior. This is another indication that Rolls is keen to stretch out and loosen the tie. As the kings of bespoke, the only limiting factors are personal taste and perhaps international law protecting endangered animal species.

This particular car has travelled the world canvassing the opinion of the people who are actually in the market for it, so needless to say the fit and finish is outstanding.

There are art deco flourishes in the instrumentation and interior trim, creating an effect overall way beyond mere transport and into the realms of Necker Island-style retreat or private jet. Which is the whole point of a Rolls-Royce; remember, you don't just the shut the rear-hinged door on one of these cars, you walk it to the chassis.

Like the Ghost, however, it still stakes out the territory between waft and genuine high performance. It uses the same powertrain as that car – rather than the Wraith's – so its 6.6-litre V12 is good for 563bhp (compared to the big coupe's 624).

Its body has gained some reinforcement, as you'd expect, although Rolls is coy about the Dawn's weight, and torsional rigidity isn't a very R-R sort of stat. We should imagine it'll feel more than adequate.

Taylor insists that the canvas roof is the 'romantic' choice on a car with this configuration, and shudders at the thought of trying to accommodate the aesthetic horrors of a folding hard-top.

"We're not just creating cars at Rolls-Royce, we're designing experiences," he says. "When you arrive somewhere, we want you to feel that you've experienced something truly special. It used to be that you'd get an idea of what it was like to be Cary Grant or Grace Kelly. The people and reference points might be different now, but we remain curators of that kind of experience."

Substitute your own names. But Taylor admits that Rolls-Royce needs to evolve, however glacially, if it's going to stay relevant. He's recently hired five new young guns to mess with the essence of the brand, carry out a bit of fashionable 'disrupting'.

"We're not this little boutique item in England that does walnut very well," he says. "We're looking well beyond the horizon, and in the next few years we'll be making a major statement about our interpretation of modern luxury."

This particular interpretation makes its world debut in Frankfurt next week, and will become a very sporadic presence on our roads from next spring. Though no prices have announced, it'll be north of the Wraith's £250,000...