Top 10 Most Unreliable Used Cars You Can Buy, According to a Leading Warranty Provider

The data says that these two belong in the same spot because although the Seat models have issues more often than the A7, when you add up the costs, mathematically, it's the same for the warranty seller.

The 8th position belongs to the last-gen Audi RS3, with a score of 32.1. It costs $3,809 on average to repair the common gearbox issues. The most expensive work done to a transmission cost almost $12,000.

The Audi RS6 C7 and early C8 models occupy the 7th most unreliable position with electrical faults that end up costing $2,606. The most financial damage came from the braking system, which set the company back $23,289. The RS6 gets a 30.3 out of 100.

Surprising or not, the Tesla Model S lands in sixth place with 25.9/100. The common electrical issues cost $1,605 on average, but one major battery defect ended up costing $12,792. In the UK, the new Tesla Model S comes with an 8-year warranty or 150,000 miles (241,401 kilometers).

The Maserati Levante sits firmly on the 5th spot, scoring just 25.3. Funnily enough, there wasn't one common issue at the root of the problem, so they differed in each version. The average cost was about 3,730 dollars, while the most expensive repair was engine-related and came to $34,920.

At number four, we have yet another Tesla, the Model X, with a score of 24.6 out of 100. The most common issue was the car's suspension, which cost the company $1,480 on average. The most outrageous amount spent on a suspension repair was $5,900.

As we enter the top 3 list, we greet the BMW M3, scoring 24.0 on the reliability chart, which surely disappoints many fans. A brand-new 2024 model with RWD that should hit 60 mph in 4.1 seconds starts from $76,000. An M3 Competition RWD is capable of getting from 0 to 60 mph in 3.8 seconds and has a price tag of $80,200. The M3 Competition xDrive engaging all four wheels costs $84,300 and hits 60 mph in 3.4 seconds.

So, how much does owning an older generation F80 (2014-2018) model cost to repair on average? Well, the common twin turbo issues from the engine can set you back a bit over 3,000 dollars. The most expensive repair was $15,184 and came via a defective gearbox.

In the second position, we have another twofer, the Land Rover Discovery 4 and 5, and the last-gen Range Rover with 22.1 out of 100. Electrical issues were the most common, making the warranty provider spend an average of $2,557 and $2,298 for the Discovery and Range Rover, respectively. The most expensive repair goes to the Range Rover, responsible for a $32,658 dent in the old bank account, while the Discovery was good for $32,198. Both cases presented with engine failures.

The number one position goes to the BMW i8 sportscar, with an incredibly low-reliability score: 16.5 out of 100. The hybrid electrical system is responsible for the most repairs, costing an average of $2,513, with a fuel system failure being accountable for the highest fixing price at 9,435 US dollars.

The most recent model from 2020 used to cost close to $150,000 and came with a 1.5-liter 3-cylinder turbocharged engine that produces 228 hp (170 kW/231 ps) with 236 lb-ft or 320 Nm of torque. Aided by an electric motor, those numbers jump to 369 hp (275 kW/374 ps). The BMW i8 Coupe could accelerate from 0 to 62 mph or 100 kph in 4.4 seconds, while the Roadster version did it in 4.6 seconds with a top speed of 155 mph or 250 kph.

So there you have it, folks, the top (or is it the bottom?) of the food chain regarding the most defective-prone car, as rated by what Mat Watson claims is the UK's leading aftermarket warranty provider. Now it's time for more bonus categories, like the least reliable city car, the 2nd-gen Smart Forfour. It scored 60.9 out of 100, which turns out to be pretty reliable, at least when we compare it to the top 10 overall spots.

This just means that every other city car from Warrantywise's data is more reliable than the Forfour, which costs $1,189 on average to repair due to the electrical system acting up. The most expensive fault came from the clutch, at $5,817.

The least reliable small hatchback is the 2nd-gen Mini Clubman with 57.8, which isn't half bad. Electrical faults are again the culprit, costing around $1,900 to repair. The most the warranty company paid was for a gearbox issue, at nearly $11,000.

The least reliable used pick-up truck in the UK is the 1st-gen Volkswagen Amarok, scoring just 41.5. In typical VW fashion, the emissions are mostly at fault here, usually costing nearly $2,000 to fix. A broken fuel system worth $6,545 was behind the most expensive repair.

The small SUV category brings the first and second-generation (2014-2021) Audi SQ5 to the podium with a score of 40.9. The fuel system is the most faulty part, and repairs cost roughly $2,564. The turbo system caused the highest bill, at $13,381.

We have the 5th and 6th generation BMW 7 Series with a 39.0 score for the limo or saloon category, which means it performed worse than the Mercedes S-Class, Jaguar XJ, or Audi A8. The average repair cost is $2,463 for suspension issues, with the highest price being $14,821 for a faulty transmission system.

Ten years from now, this list will probably be riddled only with electric cars, so it could be very fun to see what problems will plague the latest and greatest EVs circa 2035.