THE AMG KILLER? – BMW M4 Competition Convertible – Review

A devastatingly capable open-top weapon

2026 BMW M4 Competition Convertible with roof down

Forget the numbers for a second. The 2026 BMW M4 Competition Convertible is about the feeling. It’s the snarl of a 390kW inline-six hitting its stride with the sky above you. It’s the confidence of a chassis that can switch from a secure all-wheel-drive weapon to a sideways, rear-driven hooligan. It’s not perfect—its fuel range is laughably short and those kidney grilles will always have their critics. But for a driving experience that grabs you by the collar and doesn’t let go, this is an absolute masterpiece.

What Is the 2026 BMW M4 Competition Convertible?

This is Munich’s answer to a question only a few are brave enough to ask. It’s a four-seat convertible, yes, but one engineered to humiliate supercars on a circuit, soothe you on a cross-country dash, and handle the school run without drama. For 2026, the G83-generation M4 Competition Convertible gets some tech updates, but the core formula is untouched. It’s the top dog in the 4 Series drop-top range, a serious performance machine with its roof lopped off.

It slots in under the M8 Convertible in the pecking order, but we’d argue this is the more focused, more engaging car. Underneath, it shares its savage S58 engine and clever chassis with the M3 sedan and M4 coupe—this is no poseur. The big engineering job for the convertible, of course, was adding bracing to the floor and sills to replace the rigidity of a fixed roof. That work adds weight, but it’s the price of open-air thrills.

And why does it matter now? Look at its main rival. The Mercedes-AMG C63 has swapped its bellowing V8 for a turbocharged four-cylinder hybrid. The M4, meanwhile, stands its ground. It’s a last bastion of the old-school, multi-cylinder performance ethos. This convertible is for the driver who wants the wind, the noise, and the raw connection that only a great engine and a folding roof can provide.

Design and Roof Mechanism

You can’t miss it. The M4 Convertible’s face is dominated by those oversized kidney grilles. Love them or hate them, they’re less shocking in the metal these days. Flanked by sharp laser-LED headlights and featuring a muscular powerdome on the aluminium bonnet, it looks seriously aggressive from any angle. Out back, you get the classic M quad exhausts, a small lip spoiler, and swollen rear haunches hiding the staggered 19-inch and 20-inch alloy wheels.

The switch from a folding hardtop to a fabric soft-top is a big deal. This multilayer acoustic roof, in black as standard, saves about 40kg and lowers the centre of gravity. It’s quick and quiet, taking around 18 seconds and working at speeds up to 50km/h—handy if a summer storm rolls in. Roof up, the cabin is impressively hushed, feeling nearly as tight as the coupe. Roof down, it’s a different animal. The cabin opens up, and that magnificent inline-six soundtrack floods in, unfiltered.

With the roof stowed, the M4 has a clean, sleek look. No ugly, humped rear deck here. The whole stance is one of muscular elegance—it’s clearly got serious intent, but there’s a sophistication that comes with open-air motoring.

On the Road: Engine, Gearbox and Drive Modes

The star of the show is the S58 3.0-litre twin-turbo inline-six. Here, it packs 390kW and 650Nm. The engine’s personality is everything. It develops a deep, relentless shove from just above idle and screams to its 7,200rpm redline with a ferocity that belies its turbocharging. The power delivery is linear and devastating, making the car feel even quicker than its claimed 3.6-second dash to 100km/h suggests. Beyond that benchmark, its relentless pull is what truly separates it from the pack.

That engine is hooked up to ZF’s brilliant 8-speed M Steptronic auto. It’s one of the best gearboxes going. In its angriest mode, shifts are instant and savage. In comfort, they’re seamless. The gear selector itself has three levels of shift aggression, separate from the main drive modes—a simple, clever touch that lets you tailor the car’s response without fiddling with screens.

The drive modes, via the M1 and M2 wheel buttons, let you configure everything: engine, suspension, steering, brakes, and traction. Our sweet spot on Aussie roads was a softened suspension with everything else in Sport or Sport Plus. Roof down, the engine’s symphony takes over—the cracks, pops, and overrun burbles on a trailing throttle are intoxicating and perfectly synced with the gearbox’s ferocious shifts. It’s a sensory event that quieter performance cars just can’t match.

Handling, Brakes and Convertible Compromises

The big question with any convertible is shake. BMW has thrown bracing at the M4, and it works. On smooth tarmac, there’s zero shimmy through the wheel or dash. Hit a rough patch, and you might notice a slight wobble in the rear-view mirror, but it’s never distracting. The chassis feels tight, solid, and incredibly well-sorted.

The M xDrive all-wheel-drive system is rear-biased and endlessly configurable. In standard 4WD mode, it delivers immense, all-weather traction. Switch to 4WD Sport, and it sends more torque rearwards for a playful edge. The real party trick? You can fully decouple the front axle for pure rear-wheel drive. In this mode, the car’s character flips. The steering lightens, the chassis becomes a playful, adjustable tool for those who know how to use it. It’s like having two distinct performance cars in one.

The standard M Compound brakes (with red calipers) are powerful and resist fade well, but they can feel a bit grabgy in traffic, needing a smooth foot. The optional M Carbon Ceramics are another level again, but they’re a costly option. The convertible’s roughly 200kg weight penalty over the coupe is noticeable in quick direction changes, but the adaptive M suspension keeps body roll in check superbly. The near-perfect 50:50 weight distribution helps it feel agile and balanced.

Interior, Tech and Daily Usability

Inside, it’s a mix of modern tech and driver-focused design. The BMW Curved Display—a 12.3-inch digital dash and 14.9-inch touchscreen—runs the slick iDrive 8.5 system. It’s sharp, responsive, and packed with features, including wireless Apple CarPlay and Android Auto. The M-specific graphics, like the track tacho and head-up display, amp up the performance vibe.

Material quality is top-notch, especially with the optional Extended Merino leather. The heated M Sport seats are supportive for hard driving without being punishing over distance. The available M Carbon Bucket Seats look incredible but are expensive, hard to get in and out of, and not great for daily use—the standard seats are the better bet for most. A brilliant touch is the standard neck warmer vents in the front seats, making open-top driving on a crisp morning a genuine joy.

Rear seat space is tight, fine for kids or short trips. The real compromise is the boot. The roof mechanism eats into the space, leaving just 300 litres—good for soft bags, but a proper suitcase is a squeeze. With the roof up, you can use a partition to free up more room, but it’s a clear trade-off for the open-air experience. As a daily driver, it’s surprisingly capable. Even in Sport Plus, the ride is firm but not jarring on typical Aussie roads, and the refinement with the roof up makes highway cruising a quiet, refined affair.

At a Glance: How It Compares

The high-performance luxury convertible segment is packed with talent. The M4 Competition Convertible faces strong competition from its German rivals and a certain rear-engined icon. Each offers a different take on open-top speed, from hybrid tech to flat-six purity. This table lays out the key specs. BMW M4 Competition Convertible Audi RS5 Cabriolet — — A$185,000 A$170,000 3.0L twin-turbo I6 2.9L TT V6 390 kW / 523 hp 331 kW / 444 hp 3.6 s 3.9 s AWD (xDrive) quattro AWD ~10.5 L/100km ~10.8 L/100km The Audi RS5 is the value pick, offering strong V6 punch and quattro grip at a lower price, but it can’t match the BMW’s dynamic edge. The Porsche 911 is the precision instrument, with unmatched steering feel and rear-engine magic, but its price is in another league. The M4 hits a sweet spot, delivering near-supercar pace and a deeply engaging drive without the 911’s wallet-destroying cost. Its true arch-nemesis, though, is the Mercedes-AMG C63 S Cabriolet, a rivalry so close it needs a closer look.

BMW M4 Competition Convertible vs Mercedes-AMG C63 S Cabriolet: Which Is Better?

This is the German performance showdown that never gets old, and it’s more fascinating than ever. The M4 Competition Convertible starts at around A$185,000, making it a slightly cheaper entry point than the new C63 S Cabriolet, which is tipped to start north of A$200,000. That price difference alone frees up cash for some tasty options.

The on-paper performance battle is knife-edge close. The C63 S, with its plug-in hybrid 2.0-litre four-cylinder and electric motor, boasts over 500kW and a monumental 1,000Nm of system torque. That gives it a slight advantage in the 0-100km/h sprint, clocking around 3.4 seconds to the BMW’s 3.6. But figures only tell half the tale. The character of that performance is worlds apart. The BMW’s inline-six is a masterpiece—linear, eager to rev, and it howls with a metallic intensity. The AMG’s setup is brutally effective but lacks the visceral soundtrack of more cylinders. For many enthusiasts, ditching the V8 for a boosted four-pot is still a sore point.

Dynamically, the M4 is the sharper, more communicative car. Its chassis is beautifully balanced, and the switchable rear-drive mode adds a layer of adjustability the more traction-obsessed AMG can’t match. The BMW’s steering is precise, though it still can’t quite match a Porsche for feedback. The C63 S, on the other hand, uses its colossal torque and AWD system for brutal, point-and-shoot speed. It feels like a technological tour de force, while the BMW feels like a proper sports car that’s been given a convertible roof.

Inside, both are tech showcases. BMW’s iDrive 8.5 is arguably more intuitive than MBUX, but the Mercedes cabin often feels more opulent. For daily use, both are comfy, though the BMW drinks more fuel, a penalty for its bigger, non-electrified engine. The AMG’s plug-in capability is a real plus for silent, electric-only city trips.

But for a convertible buyer, the sound is everything. Roof down, the M4’s inline-six sings a song of pure, unfiltered performance. The crackles and pops on overrun are an event in themselves. The AMG’s four-cylinder, no matter how clever the tuning, just can’t replicate that drama. For many, that will be the deciding factor.

> **Which one is better?** > > **Buy the BMW M4 Competition Convertible if** you prioritise a sharp, engaging drive, crave a screaming straight-six soundtrack with the roof down, and value BMW M’s track-bred pedigree. > > **Buy the Mercedes-AMG C63 S Cabriolet if** you want the quickest straight-line acceleration, plug-in efficiency for commuting, a more lavish interior, and the prestige of the AMG badge. > > **Our pick** is the BMW. The M4’s twin-turbo inline-six offers a more authentic, thrilling performance-car experience, and its chassis is the sharper tool. The AMG’s controversial powertrain still divides the crowd.

Safety and Warranty

The BMW 4 Series platform holds a 5-star Euro NCAP safety rating (from 2019). The high-performance M versions aren’t rated separately but benefit from the same strong passenger cell. Standard safety kit is comprehensive, including Autonomous Emergency Braking, lane departure warning, lane keep assist, a driver attention monitor, and rear cross-traffic alert.

In Australia, BMW backs the M4 with a 5-year, unlimited-kilometre warranty, a strong deal that matches its key rivals. Roadside assistance is included for the same period. Servicing is condition-based, so the car tells you when it needs a check-up, typically every 12 months or 15,000 kilometres. Running costs for an M car will be higher than a standard 4 Series, but that warranty provides solid peace of mind.

Who Should Buy the BMW M4 Competition Convertible

This car is for the driver who wants it all. They’re after a thrilling, track-capable weapon that can also do the daily grind and look glamorous with the roof down. They value engineering integrity, driver involvement, and a great soundtrack—that S58 with the roof stowed is a core part of the appeal. They might have a young family or need occasional rear seats, but the driving experience is their number one.

They know and accept the trade-offs: the thirst, the limited boot, the bold styling. They’re not chasing ultimate comfort or efficiency; they’re chasing the ultimate open-air, high-performance driving experience with a badge that demands respect on road and track.

FAQ

How much does the 2026 BMW M4 Competition Convertible cost in Australia?

You’re looking at a starting price of around A$185,000 before on-roads and any optional extras.

Is the M4 Convertible faster than the C63 Cabriolet?

On paper, the AMG has a slight edge, doing the 0-100km/h dash in about 3.4 seconds compared to the BMW’s 3.6 seconds.

Does the M4 Competition Convertible only come with all-wheel drive?

In its standard Competition xDrive form, yes. But the system’s party trick is that you can fully switch it to rear-wheel drive through the menus.

What is the top speed of the BMW M4 Competition Convertible?

It’s electronically limited to 250km/h, but tick the box for the M Driver’s Package and that rises to 290km/h.

How much boot space does the M4 Convertible have?

With the roof up, you get about 300 litres. With the roof down, that space shrinks considerably.

What warranty does BMW Australia offer on the M4?

BMW Australia provides a 5-year warranty with no kilometre limit.

Is the BMW M4 Competition Convertible a good daily driver?

Absolutely. It’s surprisingly comfortable in its softer settings, quiet with the roof up, and the all-wheel-drive system gives you confidence in all conditions. Just keep an eye on the fuel gauge.