The legendary Mercedes-Benz S-Class has for decades been the ultimate luxury limo. These days, it’s not just sold as an indulgent four-door, though. The two-door coupe has already provided stern competition for the Bentley Continental GT, and now there’s a new S-Class Cabriolet to extend the appeal to rich sun-seekers.

You can get it with three suitably high-end engines. We’re talking a 4.7-litre turbo V8 even for the entry-level S 500 here. If that’s not enough, take a twin-turbo 5.5-litre V8 S 63 AMG, or a breathtaking 6.0-litre turbo V12 in the S 65 AMG. Here, we’re sticking with the regular car which, at £110,000, will take the bulk of sales.

The S 500’s V8 is brilliant. It is hushed cruiser and genuine performance car all in one. It can do 0-62mph in just 4.7sec, yet you’d never believe it when lolloping along the motorway. This is a 2.1-tonne car, but one you’d scarcely believe weighs so much.

Just as surprising is how the air suspension manages to blend comfort and crispness. The ride is exceptional, with indulgence and suppleness that flatters even the worst British roads. Yet with level body control and surprising turn-in alacrity, it’s more fun through the bends than you’d think.

Ultimately, you’ll eventually feel the weight and size of the S 500. It can’t overcome physics. But it can keep the effects remarkably at bay, making it a much more rewarding car to drive than you’d perhaps expect. It’s near-silent when doing so, too – it’s easily the quietest convertible on sale. Lowering the roof, which takes 20 seconds at speeds of up to 30mph, hardly spoils things either.

The tech-laden interior of the regular S-Class is carried over to this Cabriolet. The driver faces two ultra-large screens, through which most of the car’s functions are masterminded. But it’s not all tech. Leather is everywhere, there’s an abundance of tactile metal finishes and everything feels high-end and luxurious.

You’ll not want for any equipment, either. The test AMG Line model had air suspension, climate control, 19in alloy wheels, LED headlights, sat nav and full leather all as standard. And that’s just for starters. Take it from us, you won’t be needing to hit the options list with this car…

Cosseting seats up front adjust in every which way. Those in the rear aren’t quite as lavish, and front-seat passengers will have to trade some of the cavernous space they enjoy for rear-seat comfort. One adult behind another is a tight squeeze.

The boot is impressive with the roof up: 400 litres is bigger than a VW Golf. There’s a divider that needs to be put in place before lowering the roof, though – and this significantly impacts upon overall capacity. It turns a commendable space into something fit for only a couple of soft weekend bags. Travelling four-up for a weekend? Everyone best pack light.

But how they’ll be lavished with top-notch luxury experience en route. The S-Class cabriolet is an exceptional car, a genuine luxury machine that, alongside the £44,000 more expensive Bentley Continental GTC, somehow manages to look an absolute bargain. Yes, despite its £110k list price.

The S-Class range has long set the luxury car benchmark. In chopping off the roof, Mercedes-Benz has done nothing to alter this. Looking for the finest luxury four-seat convertible on sale? Look no further.