The pool of customers who want and can afford a Mercedes S-Class Cabriolet is always going to be relatively small. Buying one is costly and self-indulgent purchase, intended for those who really want the finer things in life. 

It should appeal to those who find sports cars like the Ferrari California T too dramatic, but still want a big convertible that offers substantial performance. The unbridled luxury of the Mercedes-Benz S-Class Cabriolet is what sets it apart, from the supportive front seats to the cosseting air suspension.

It also makes the Mercedes-Benz S-Class Cabriolet usable every single day, whether that be for commuting to work or making a lengthy trip to your country estate. 

Attempting to pick the best Mercedes-Benz S-Class Cabriolet to buy is like trying to decide which dish to order in a Michelin-starred restaurant. All of them are going to be good, it just depends on what your personal taste (and budget) will allow. 

With that in mind, it is hard to ignore the entry-level version of the Mercedes-Benz S-Class Cabriolet over the two AMG models. Calling it ‘entry-level’ does it a huge disservice, given that it features standard equipment such as air suspension, intelligent LED headlights and even laminated window glass to insulate against heat and noise. 

Initially branded as the S 500 AMG Line, the first step on the Mercedes-Benz S S-Class Cabriolet ladder became the S 560, and later the S 560 Grand Edition. A turbocharged V8 engine is common to them all, and packs plenty of punch despite the size of the car.

The blend of luxury, grand proportions and impressive performance actually place the Mercedes-Benz S-Class Cabriolet in something of its own niche. 

The closest German rival is the BMW 8 Series Convertible, but the Mercedes is far more luxurious and extravagant by comparison. A Bentley Continental GTC is similar in ethos to the Mercedes-Benz S-Class, but prices begin much higher than the amount asked for the range-topping AMG variant. 

The same is true of the Aston Martin DB11 Volante, which also costs more than the top-ranking Mercedes-Benz S-Class. Whisper it, but the DB11 also uses a V8 engine supplied by the AMG department at Mercedes-Benz.

As a range-topping model, Mercedes ensured that the Mercedes-Benz S-Class Cabriolet looked and felt suitably classy. Wooden trim elements sweep elaborately from one side of the dashboard to the other, with leather covering huge swathes of the centre console and doors. It all looks expensive to begin with, but buyers can specify optional extended leather packages to cover even more surfaces with exclusive Nappa hide. 

Certain AMG models can have carbonfibre trim specified for the dash, but it doesn’t quite work in the confines of the Mercedes-Benz S-Class Cabriolet. These sportiest models also gain the AMG logo embossed into the front armrest, plus illuminated door sills. 

Plump for the range-topping AMG S 65 model and the quality will be upped by the addition of special LED headlights. These feature 47 separate Swarovski crystals in each headlight, ensuring that everyone knows you bought the most expensive version. 

That Mercedes-Benz feels confident to fit such ostentatious features to the Mercedes-Benz S-Class Cabriolet is testament to how proud it is of the car. Everything feels built to last, and those on the hunt for flimsy plastics will be out of luck here. 

The centrepiece of the Mercedes-Benz S-Class Cabriolet’s interior is the widescreen display that covers both the multimedia system and the gauges ahead of the driver. Comprising two separate 12.3-inch screens on a single pane, the style has now been borrowed by cheaper Mercedes-Benz models. However, it still looks good and works well here.

All Mercedes-Benz S-Class Cabriolets come fitted with the Comand Online system as standard. This means DAB radio, Bluetooth connectivity, a DVD player and hard drive-based satellite navigation – all handled from the same system. The connected functions include access to live traffic information, weather reports and directions from Google Maps. 

Controlling all this is a rotary and touchpad device on the centre console, surrounded by a ring of buttons. The steering wheel also features miniature touchpads, and voice commands can also be given. Such huge functionality can be overwhelming at first, but familiarity makes using the Comand system much easier. 

All but the entry-level S 500 benefit from a Burmester surround-sound audio system. On the range-topping AMG S 65, it comes with 24 separate speakers, plus an amplifier capable of generating an output of 1,520W. It is seriously loud.

Later models have wireless charging capabilities for smartphones, while all versions can use Near Field Communication to quickly connect devices to the car.

Despite the big dimensions of the Mercedes-Benz S-Class Cabriolet, don’t be fooled into thinking this is a practical car with acres of storage space. 

The transition from four-door saloon to two-door convertible has seen plenty of real estate go missing, with only those in the front seats having plenty of room.

Up front, both driver and passenger should feel suitably accommodated in the Mercedes-Benz S-Class Cabriolet. A large centre console runs the full length of the cabin, and provides a sizeable storage compartment beneath the front armrest. Cup holders, door bins and a glovebox provide storage options for smaller items. 

In the rear, space is at much more of a premium. Legroom is restricted for taller passengers, due to the substantial nature of the front seats. Shorter trips should be fine, but longer journeys may generate complaints. 

Head and shoulder room should not be an issue in the rear with the roof raised. Back-seat passengers also benefit from the full-length centre console, with armrests and storage spaces provided. Access to the rear is also relatively painless, with the front seats folding and sliding forward quite far. 

The back row can take two child seats, with ISOFIX mountings provided. Turning up in the Mercedes-Benz S-Class Cabriolet on the school run would certainly make for a dramatic entrance outside the school gates. 

With a large folding soft-top roof, the Mercedes-Benz S-Class Cabriolet needs somewhere to store the mass of fabric and the mechanisms that make it work. Mercedes has designed it with a smooth rear deck, meaning everything slots into the space otherwise occupied by luggage.

Compared to the Mercedes-Benz S-Class Coupe, which has 400 litres of boot space, the Mercedes-Benz S-Class Cabriolet offers 350 litres. Although not huge, this is comparable to similar cars such as the Bentley Continental GTC. Dropping the roof also eats further into the boot space, meaning you will need to pack carefully. 

Given the limited space in the back for passengers, using them to store additional luggage may be a better use of them. 

The limited space in the rear and boot, is potentially the only major drawback to the  Mercedes-Benz S-Class Cabriolet. Such a contrast between large external dimensions and interior space is hard to ignore. Yet, given the nature of the big convertible, practical considerations are unlikely to put many buyers off.

The Mercedes-Benz S-Class Cabriolet dimensions are 5027mm long, 2108mm wide and 1420mm tall.

When a 4.7-litre twin-turbocharged V8 engine happens to be the entry-level option, you know how serious Mercedes-Benz is about the Mercedes-Benz S-Class Cabriolet.

The S 500 produces 455PS, allowing the car to accelerate from 0-62mph in just 4.6 seconds. It is hugely flexible, making the Cabrio feel quick in almost all circumstances. It comes with a nine-speed automatic gearbox as standard. Like all Mercedes-Benz S-Class Cabriolets, it is limited to a top speed of 155mph.

In 2018, Mercedes replaced the S 500 with the S 560. It features a twin-turbocharged 4.0-litre V8, making 469PS. It has the same 9G-Tronic gearbox, and still runs from 0-62mph in 4.6 seconds. 

Even quicker is the AMG S 63. Pre-2018 models use a twin-turbocharged 5.5-litre V8 with 585PS. It uses a nine-speed AMG Speedshift MCT gearbox, allowing quicker gear changes. 

After 2018, the AMG S 63 gained a modified version of the 4.0-litre twin-turbo V8. More power was the order of the day, with output taken to 612PS. However, the 0-62mph time remained the same as the previous version, at 4.2 seconds.

Topping the performance scale is the ludicrous AMG S 65. Mercedes-AMG installs a 6.0-litre V12 engine, fitted with twin-turbochargers. The result is 630PS and an eye-watering 1000Nm of torque, with a seven-speed AMG automatic gearbox. 

Despite all this, it only shaves the 0-62mph time down to 4.1 seconds. But it almost doesn’t matter, as buying the AMG S 65 is about owning the most indulgent version of the Mercedes-Benz S-Class Cabriolet possible.

Most convertibles suffer from an increase in noise and reduction in overall refinement from having a folding fabric roof. Not so the Mercedes-Benz S-Class Cabriolet. This is not just one of the most refined convertibles, it edges towards being one of the most refined cars full-stop. 

Very few other convertibles have features like laminated sound-insulating glass fitted as standard. With the roof in place, outside noises are barely perceptible, while engine noise is minimal. 

Lowering the roof hardly has a dramatic effect on the level of noise experienced. Mercedes fits the impressive Aircap system as standard to all Mercedes-Benz S-Class Cabrios. This uses a pop-up spoiler on top of the windscreen, combined with a wind deflector mounted behind the rear seats. It deploys at the press of a button, and helps eliminate annoying draughts inside the cabin.

Exhaust noise from the AMG S 63 can be tailored to suit just how extravagant you are feeling. It has two sound settings, which change depending on the driving mode selected. Sport mode and beyond delivers a much louder experience, complete with pops and crackles from the chrome tailpipes. The sound from the snarling AMG S 65 is on another level again.

Mercedes-Benz has often used the S-Class to pioneer safety technology, and the same continues with the Mercedes-Benz S-Class Cabriolet. There is a whole host of airbags fitted as standard, including side airbags for both front and rear passengers. Although Mercedes-Benz has not had the S-Class tested by Euro NCAP, there is little reason to doubt it would perform extremely well in a crash.

The Mercedes-Benz S-Class Cabriolet can read traffic signs itself, detect if the driver is at risk of falling asleep, and even correct itself should a crosswind affect the stability of the car. 

As part of the model update in 2018, the Mercedes-Benz S-Class Cabriolet gained upgrades for its semi-autonomous driving capabilities. Offered as part of the Driving Assistance Package, it allows the Cabrio to automatically stay in the centre of a lane, even when going around corners. It can also steer to avoid hazards picked up by the Blind Spot Assist or Lane Keeping Assist.

The Driving Assistance Package is standard on AMG models, and optional on others. It also includes a 360-degree camera, active cruise control, and systems to start braking automatically should the car detect the risk of a collision.

Fixings on the two rear seats of the Mercedes-Benz S-Class Cabriolet are provided for child seats. On earlier cars these are ISOFIX attachments, which were upgraded to the newer i-Size fitments on post-2018 models. An automatic child seat recognition sensor is fitted as standard, too. There is no spare wheel, but Mercedes-Benz does supply a tyre-sealant kit and compressor.

The Mercedes-Benz S-Class Cabriolet was too niche to appear in the HonestJohn.co.uk Satisfaction Survey, but the saloon version on which it is based achieved a disappointing 8.86 out of 10 for reliability, making it something of a poor performer compared to other models from the brand. This is largely down to the number of complicated systems it runs that need regular maintenance to stay in good health.

As a brand Mercedes-Benz finished a respectable 13th out of 30 manufacturers overall, but this might be lower than you would expect from a brand that is traditionally thought of as being well-engineered.

Summarising the insurance groups for the Mercedes-Benz S-Class Cabriolet is a fairly simple affair, and one with an expensive answer. 

Given the substantial performance, premium badge and overall expense involved, it should be no surprise that all models claim the top insurance group. This means all versions from the S 500 AMG Line through to the AMG S65 are rated as group 50 for insurance. 

An alarm with interior protection is standard on all Mercedes-Benz S-Class Cabrios, as is remote vehicle tracking as part of the Comand Online system. However, investing in a standalone vehicle tracker is advisable.

As with most running costs relating to the Mercedes-Benz S-Class Cabriolet, VED (road tax) is another expense likely to involve large sums of money. 

Some of the earliest S 500 AMG Line cars, sold from July 2016 onwards, fall into the pre-April 2017 VED scheme. This makes them liable for an annual rate of £360.

All other models fall into the newer scheme, with the list price of the Mercedes-Benz S-Class clearly exceeding the £40,000 barrier. This means after the first year, all cars are subject to the additional £355 annual charge levied on top of the regular £165 fee, for five years.

Mercedes-Benz has managed to incorporate a number of subtle changes into the various trim levels of the Mercedes-Benz S-Class Cabriolet. 

The Mercedes-Benz S-Class Convertible AMG Line was the entry point into ownership, bringing LED headlights, leather seats, the Comand Online multimedia system, air suspension and 19-inch wheels. An optional Premium Package could add 20-inch wheels, the Burmester sound system and front seats with a massage function.

Also available was the Mercedes-Benz S-Class Convertible S 500 Night Edition, wearing special grey paint with a matt finish, 20-inch black alloy wheels and a black radiator grille. 

The Mercedes-Benz S-Class Convertible Grand Edition became the entry point of the range and came with 20-inch wheels, a 360-degree parking camera, the Burmester sound system and wireless phone charging. 

Choosing a Mercedes-Benz S-Class Convertible AMG S 63 brings unique body styling, an AMG sports exhaust and an interior fitted with AMG sports seats. Going all out with the rare AMG S 65 adds a special front bumper, LED headlights with Swarovski crystals, plus sports seats finished in exclusive Nappa leather. 

All versions are packed with equipment, meaning there is very little to choose between them. Buying based on the engine performance you want, rather than additional features, makes most sense.