What Car? Reliability Survey: Most and least reliable coupés, convertibles and sports cars

Coupés, convertibles and sports cars are cars you buy for fun, but getting one that's unreliable and costly to keep on the road will quickly dent your enthusiasm. 

The good news is that most of the cars in this class are pretty robust, providing fault-free driving for most owners. The most common problems owners complain about are with the bodywork and various electrical systems. In many instances cars are fixed for free and they don't linger in the workshop for too long. 

This is why the class has had a high average score of 92% for the past couple of years, which is better than many other classes, including executive and luxury cars and seven-seaters.  

Some sports cars, such as the Audi TT and Porsche Cayman and Boxster, frequently appear at the top of the chart. It's not all about svelte coupes and roadsters, though, some four-seaters, such as the latest BMW 4 Series Coupe and Convertible and the Mini Convertible, are also regulars at the top of this category.  

For this story, we've pulled out all the data for coupés, convertibles and sports cars aged up to five years old. 

The 2025 What Car? Reliability Survey is live, tell us about your car now

Most reliable coupés, convertibles and sports cars

1. Porsche Boxster / Cayman (2016-present)

Reliability rating 99.3%

• Most common faults: Bodywork 6%

• Average repair cost: £0

• Typical time off road: 100% one day or less

The Porsche Boxster drop-top and its coupe brother the Cayman are both sensational to drive and extremely well-built. They come with a choice of powerful petrol engines and the option of a manual gearbox as well as the PDK automatic gearbox. Equally unusual for a sports car is the fact that they have two boots, one at the front and one at the rear, so they are a bit more practical than some rivals. 

The Boxster and Cayman have been at or near the top of our sports car reliability chart for some years, demonstrating the long-term durability of the pair. In the latest survey, owners told us that just 6% of their cars went wrong, and the only area to give cause for concern was the bodywork. 

Owners were kept happy because all fixes were carried out for free, and all work was completed in a day or less.  

Owner’s view: “I really appreciate my car’s build quality and reliability.”

Porsche Boxster review / Porsche Cayman review

2. Mini Convertible (2016-2024)

Reliability rating 99.2%

• Most common faults: Sat-nav/infotainment system 7%

• Average repair cost: £0

• Typical time off road: 100% one day or less

This generation of the Mini Convertible has been replaced, but it still makes a great used buy because it's stylish, fun to drive and extremely robust. There isn’t a bad option in the engine range. Even the entry-level petrol – a turbocharged 1.5-litre three-cylinder – is punchy, quiet and economical. The 2.0-litre in the Cooper S is more lively, and the high-performance John Cooper Works model is great fun. 

It's not the roomiest drop-top, though, with limited rear seat space and a titchy boot. However, front seat occupants are well catered for, with lots of adjustment in both the seats and steering wheel to allow even the tallest people to find a comfortable position.

According to our data, the Mini Convertible doesn't go wrong often: only 7% of owners said their cars had suffered any problems. The only area concerned was the sat-nav/infotainment system, and all issues with this were sorted out in a day or less at no cost. 

Used Mini Convertible review

=3. BMW 4 Series Coupe / Convertible (2020-present)

Reliability rating 98.4%

• Most common faults: Non-engine electrics 7%, steering 2%

• Average repair cost: £0

• Typical time off road: 25% one day or less, 75% one day to a week

The latest BMW 4 Series Coupe has superb performance and handling and a smartly appointed interior.  The same can be said for the 4 Series Convertible, which is also more practical than the previous model because it has a fabric roof that stows away more compactly than its predecessor's folding metal roof.

Both the 4 Series Coupe and Convertible are proving far more reliable than the previous model, too, which languishes at the bottom of this class with a reliability rating of 79%. 

Only 8% of the 4 Series models reported on in our survey had any glitches. Most were with the sat-nav/infotainment system, but there were some problems with the steering system, too. Although it took up to a week to put most problems right, BMW covered the cost of all remedial work. 

BMW 4 Series Coupé review / BMW 4 Series Convertible review

=3. Audi TT (2014-2024) 

Reliability rating 98.4%

• Most common faults: Exhaust system 8%

• Average repair cost: 50% cost £0, 50% cost £1-£50

• Typical time off road: 50% one day or less, 50% more than a week

Many car enthusiasts will lament the demise of the Audi TT because it's brilliant to drive and effortless to live with. Whether you choose the two-seater Roadster version or the slightly more practical four-seat Coupe, you'll get a car that's a great all-rounder with crisp handling, efficient engines and a smart interior. 

As well as being one of the most dependable sports cars, the TT is also the highest-scoring Audi model for reliability, outshining more expensive models, such as the Audi A4 and A6. 

According to TT owners, only 8% of their cars had any issues, and all of those were with the exhaust system. Audi covered the cost of 50% of repairs, and the remaining owners had bills of less than £50 per fault. Half of faulty cars were fixed in a day or less, but the rest took more than a week to put right. 

Used Audi TT Coupé review / Used Audi TT Roadster review

5. BMW 2 Series Coupé/Convertible (2014-2021) 

Reliability rating 98.2%

• Most common faults: Bodywork 3%, engine 3%

• Average repair cost: £0

• Typical time off road: 50% one day to a week, 50% more than a week

Whether you choose the BMW 2 Series Coupé or Convertible you'll get a comfortable, fun-to-drive sports car that's also good value used. Both body styles have a compliant ride, sharp handling and strong performance. Neither are particularly roomy for rear seat passengers though, but the back seats are acceptable for children or short journeys for adults. 

The other good thing about the 2 Series is its reliability: its rating of 98.2% is only just behind that of the pricier BMW 4 Series. Only 7% of the 2 Series models reported on had any problems, and these were restricted to the bodywork and engine. Half of cars were rendered undriveable by their faults, and these examples took more than a week to fix. The rest were out of the garage in less than a week. 

The good news is that BMW paid for the repairs in all cases. 

Used BMW 2 Series Coupe / Used BMW 2 Series Convertible review

6. Toyota GR Yaris (2020-present) 

Reliability rating 97.4%

• Most common faults: Non-engine electrics 5%

• Average repair cost: £201-£300

• Typical time off road: 100% more than a week

The GR Yaris is one of the most characterful and entertaining hot hatches of the decade. Although it shares its name with Toyota's small hatchback, it shares very little else with the more mundane model. It's more powerful than larger hot hatches, such as the Honda Civic Type R and Renault Megane RS, and can complete the 0-62mph sprint in 5.5sec. 

One thing it has in common with other Toyota models is excellent reliability. A mere 5% of the cars in our survey had a problem, and they were restricted to non-engine electrical issues. While all cars could still be driven, they were in the workshop for more than a week being fixed. Although Toyota didn't cover the cost of every repair, all bills were below £300. 

Toyota GR Yaris review

7. Mercedes CLA (2019-present) 

Reliability rating 96.2%

• Most common faults: 12-volt battery 10%, bodywork 5%, non-engine electrics 5%, sat-nav/infotainment system 5%

• Average repair cost: £0

• Typical time off road: 20% one day or less, 80% one day to a week

The CLA is a coupe version of the Mercedes A-Class saloon. While it retains the efficient engines and high-tech interior of its saloon counterpart, it adds a touch of style with its sleeker roofline. Although it's not as roomy as the saloon, there is plenty of space up front for a six-footer and it has a roomy boot. 

It's also one of the best Mercedes models for dependability, ranking above the larger E-Class Coupé, which scores 84.3%. Overall, 10% of the CLAs reported on had a fault, with the 12-volt battery the main culprit. Mercedes paid for all repairs, but most cars took up to a week to put right. 

Mercedes CLA review

8. Volkswagen Arteon (2017-present) 

Reliability rating 91.0%

• Most common faults: Sat-nav/infotainment 17%, suspension 9%, bodywork 4%, brakes 4%, non-engine electrics 4%

• Average repair cost: 89% cost £0, 11% cost £101-£200

• Typical time off road: 33% one day or less, 44% one day to a week, 22% more than a week

If you want a stylish coupé that's also roomy and practical, the Volkswagen Arteon may fit the bill. That's because it’s based on the Passat, and that helps it in the space stakes: its rear seats are far roomier than those in an Audi A5 Sportback or a BMW 4 Series Gran Coupé.  

However, it goes wrong more often than it should: owners told us 30% of their Arteons had to go back to the dealer for a fault. While the infotainment system accounted for a lot of problems, there were also issues with the bodywork, brakes and suspension. 

Volkswagen took the sting out of the faults for most people: 89% of glitches were fixed for free. Repairs weren't the swiftest, though, with only 33% of cars sorted out in a day or less, and most taking up to a week to put right. 

Volkswagen Arteon review

9. Mazda MX-5 (2015-present) 

Reliability rating 91.5%

• Most common faults: Non-engine electrics 9%, 12-volt battery 6%, engine electrics 3%, suspension 3%

• Average repair cost: 29% cost £0, 57% cost £51-£350, 14% cost £301-£750

• Typical time off road: 43% one day or less, 57% up to a week

The much-loved MX-5 sports car is great to drive and doesn't cost a fortune to buy. It has an excellent balance of ride and handling and,although it's not as rapid as some high-octane sports cars, it has enough oomph to be fun on twisty roads. It is a strict two-seater, though, with minimal storage and boot space. 

Electrical issues were the main bugbear of the 21% of MX-5 owners who told us their cars had gone wrong. However, it's the high cost of some repairs and the length of time in the workshop that pull the MX-5's score down. Mazda only covered the cost of 29% of repairs, leaving most owners with bills of up to £350, and some having to find up to £750. While nearly half of problems were rectified in a day or less, the rest took up to a week. 

Mazda MX-5 review

10. Porsche 911 (2019-present)

Reliability rating 88.5%

• Most common faults: Bodywork 20%, 12-volt battery 12%, sat-nav/infotainment system 12%, interior trim 4%, non-engine electrics 4%

• Average repair cost: 77% cost £0, 15% cost £1-£50, 8% cost more than £1500

• Typical time off road: 54% one day or less, 31% one day to a week

This iconic sports car is thrilling to drive, yet remarkably easy to live with. It's seriously rapid, great to drive on all types of roads and pretty practical for a sports car, with two small rear seats on most versions and a reasonably sized luggage space under the bonnet. 

It's not the best Porsche model for reliability, though, that accolade goes to the more affordable Boxster and Cayman. 911 owners told us that 40% of their cars had a problem, with the most complaints being about bodywork issues. 

While Porsche paid for the repairs on 77% of cars, some owners had to pay a small amount, and 8% were charged more than £1500 to get faults fixed. At least most remedial work was done quickly: 54% of issues were put right in a day or less and most were sorted out in less than a week. 

Porsche 911 review

Least reliable coupés, convertibles and sports cars

1. BMW 4 Series Coupé and Convertible (2014-2020)

Reliability rating 79.0%

• Most common faults: Bodywork 14%, 12-volt battery 7%, air-con 4%, brakes 4%, engine 4%, fuel system 4%, non-engine electrics 4%

• Average repair cost: 33% cost £0, 24% up to £750, 17% £1001-£1500, 8% more than £1500

• Typical time off road: 50% more than a week, 33% one day to a week

The previous generation BMW 4 Series Coupé and Convertible are desirable models with sharp handling and smooth looks. The pair are based on the same underpinnings as the 3 Series saloon, which is a good thing because it means they're available with a wide range of strong petrol engines. However, they suffer from far more issues than their four-door cousin. 

Costly repair bills and long stints in the workshop were the main headaches for the 25% of owners who told us their cars had gone wrong. Only 33% of faults were fixed for free, leaving most owners with bills of up to £750 and 25% having to find more than £1000 to put things right. Although most faulty cars could still be driven, half of them took more than a week to fix.

Owner's comment: "My car has an ongoing issue; it’s now in the garage for the fifth time for the same fault."

Used BMW 4 Series Coupé / Used BMW 4 Series Convertible review

2. Mercedes E-Class Coupé (2017-present) / E-Class Cabriolet (2017-2023)

Reliability rating 83.4%

• Most common faults: 12-volt battery 20%, suspension 20%, sat-nav/infotainment system 13%, interior trim 7%

• Average repair cost: 73% cost £0, 27% cost £101-£350

• Typical time off road: 64% one day or less, 36% more than a week

The E-Class Coupé and Cabriolet aren't the most exciting cars to drive, but they're both supremely quiet, comfortable and refined. They are based on the same underpinnings as the E-Class Saloon and share its engines and equipment. 

However, the E-Class Coupé and Cabriolet don't share the saloon's reliability record. Their score is nearly 10% lower than that of the E-Class saloon, and they went wrong far more often: 47% of Coupé and Cabriolets had a fault, compared with 25% of saloons. 

Two areas of the car gave the most trouble: the 12-volt battery and the suspension. There were also complaints about the infotainment system. Nearly three-quarters of problems were fixed for free by Mercedes, but some owners were left with bills of up to £350. Around two-thirds of cars were put right in a day or less, though. 

Used Mercedes E-Class Coupé / Used Mercedes E-Class Cabriolet review

3. Jaguar F-Type (2014-present)

Reliability rating 88.3%

• Most common faults: Non-engine electrics 9%, air-con 4%, engine electrics 4%, exhaust 4%, sat-nav/infotainment system 4%

• Average repair cost: 67% cost £0, 33% cost more than £1500

• Typical time off road: 33% one day or less, 67% more than a week

The Jaguar F-Type is a real head-turner, great fun to drive and pretty good value as a used buy. Some rivals are better to drive, but the F-Type has lashings of old-school charm and an enticing exhaust note.

However, your enjoyment may be hampered by the expensive repair bills and long stints in the workshop that 21% of F-Type owners told us about. It's the second lowest-scoring Jaguar model after the 2015-2024 XE executive saloon. 

A range of electrical woes were the main bugbears of the F-Type, followed by problems with the air-con, exhaust system and infotainment. While Jaguar covered the cost of two-thirds of remedial work, that left a third of owners with bills that exceeded £1500. That was made worse by the fact that two-thirds of faulty cars were out of action for more than a week. 

Jaguar F-Type review

Reliability of coupés, convertibles and sports cars aged up to five years old

To read the reliability data for other car classes follow these links:

Most and least reliable cars overall (2024)
Most reliable car brands (2024)
Most reliable small cars (2024)
Most reliable family cars (2024)
Most reliable executive cars (2024)
Most reliable luxury cars (2024)
Most reliable small SUVs (2024)
Most reliable family SUVs (2024)
Most reliable large SUVs (2024)
Most reliable seven-seaters (2024)
Most reliable electric cars (2024)
Most reliable electric SUVs (2023)
Most reliable diesel cars (2023)
Most reliable petrol cars (2024)
Most reliable hybrid cars (2024)

How we compiled the survey

The latest What Car? Reliability Survey gained 29,967 responses and that enabled us to report on 199 models (up to five years old) from 31 different brands. 

To compile the survey, conducted in association with MotorEasy, we ask thousands of car owners to tell us how well their cars had behaved over the previous 24 months. 

For every car that has suffered a fault, we ask in what area the issue occurred, plus how much it cost to repair and how long it spent in the workshop. This information is used to create a reliability rating for each model and brand where we have a large enough response rate.

About the report author

Claire Evans has been a motoring journalist for more than 30 years, and has focussed on consumer issues for much of that time. She was the advice columnist for Carweek magazine in the 1990s, helping car owners with faulty cars get the right level of reparation from car makers.

She also spent six years working on motoring content for Which?, and it is here she oversaw the running of the charity's annual used car reliability survey.

Claire launched the What Car? Reliability Survey in 2017, and since then has helped thousands of buyers choose the most reliable new cars and SUVs, as well as the most dependable used cars.

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