Perhaps there will always be a market for the grandiose, for cars as big as yachts, houses as big as palaces, diamonds as big as the Ritz. In some circles, scale still equates to status, and cars are especially susceptible to this trope.

One particular niche that dropped off precipitously in the modern era was the super-sized convertible. Although open-topped cars proliferate on the world's roads, especially in markets like the American coasts and, surprisingly, the UK, the days of majestic canvas roofs furled back to reveal their gilded occupants have all but vanished. Instead, you can't move for convertible hatchbacks and airy two-seaters, leaving open cars that can seat four with ease very thin on the ground. There's the Rolls-Royce Dawn, of course, and a brace of mid-market saloon conversions that don't quite hit the spot for the back seat passengers – too many compromises and not nearly enough style.

Mercedes-Benz hopes to change all that. The company first hinted at the return of the grand convertible with the Ocean Drive concept back in 2007; a four-door drop-top S-Class that harked back to its last brush with open air exclusivity, the grand 300d Cabriolet of 1962. The economic downturn put paid to the Ocean Drive becoming a reality, but the die was cast. An all-new S-Class arrived in 2014 as both saloon and coupé; and now we finally have the Cabriolet, a full-size four-seater that splices old-fashioned glamour with technological overkill.

Maybe overkill isn’t quite the right word, but the truth is that keeping such a sizeable beast on the straight and narrow involves an enormous amount of engineering, not to mention raw power. The sleek lines and leather, wood and chrome interior could almost have come out of the Jazz Age. Yet, lurking just beneath that trim is a suite of electronics that puts Mercedes at the forefront of autonomous technology.

The S-Class Cabriolet has it all, from radar-controlled cruise through to an efficient self-steering system that'll do its damnedest to keep the car on the road without any input from you whatsoever. Flagship vehicles are typically showcases for gadgets that'll ultimately filter down the status strata until they find a place in every car. In the past, the S-Class has heralded technical firsts like ABS and an all-LED lighting system. The presumption here is that self-driving will gradually percolate through the whole market, until even the humblest family car can keep itself up with traffic just as this Mercedes can.

All this intensive technology slightly detracts from the fact that the S-Class Cabriolet is a pleasure to drive. V8 power is deployed effectively to make the monster feel lighter and defter, but in 'standard' S500 form this never feels like a car you want to hustle along some winding roads. The AMG model is more focused and raucous, but unless you demand bragging rights you’ll find that the S500 is more than enough. Modern luxury is fluid, and right now the big Benz is at the crest of a wave. There’s every indication that the company will continue to shape the sybaritic style of tomorrow.