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Nobody wants to buy an unreliable car. Not just because it could let you down at any given moment but the unavoidable repair costs you will encounter tend to pile up.
Fortunately, we can exclusively reveal new data to tell you which 10 cars are most likely to suffer from dependability issues - but also the ones that are best at avoiding them.
And not only that, we can tell you what the most common problems are with the unreliable models and when they're most likely to strike - just so you can prepare for the inevitable garage bills if you do own one.
UK used car warranty provider Warranty Wise has given This is Money the list of the 10 most unreliable second-hand motors you could buy, based on the number of claims against faults and how much they cost.
'This data is not fictitious, it is derived from real cases and genuine warranty claims making it the most trustworthy information a used car buyer can get,' a spokesperson for the brand told us.
'We are not suggesting, by any means, that these problems are guaranteed to occur, but it is the sole reason a warranty exists.
'A proper, comprehensive warranty provides peace of mind to any buyer forewarned with this type of information, making any used car purchase a less risky and more comfortable experience.'
Each year, it lists the brands and models that are deemed the most and least reliable, according to the data it has collated in the previous 12 months.
Scroll down the page to find out which models and brands that have the fewest warranty claims for repair bills.
10 MOST UNRELIABLE MODELS
The Range Rover Sport is a pricey SUV that's used by most for the school run rather than scaling mountain rises or trawling through fields.
That said, many still incur plenty of issues which tend to be expensive to repair.
Warranty Wise ranks it as the least dependable model you can drive, with the most common problem being suspension faults, which costs around $1000 to fix.
When problems start to pile up: when a car is 8 years and 7 months old
The Zafira is probably a car you've decided to avoid already - or you would have done if you'd Googled it. The family-friendly MPV has been subject to recalls following a spate of fires that have occurred, mainly caused by aftermarket replacement parts.
And turning into a fireball on wheels isn't all that owners need to be concerned about. That's because this Vauxhall suffers some catastrophic gearbox issues, which cost on average over $1900 to resolve.
When problems start to pile up: when a car is 10 years and 3 months old
Vauxhall's second entry in the unreliable car list is the Insignia - a favoured rep mobile that's likely to have been slogged up and down the motorway in the week and used to cart the family around at the weekend.
According to Warranty Wise, it's steering faults that are most common, though the repair costs around $522, there are other frequently reported issues that cost almost five times as much to fix.
When problems start to pile up: when a car is 7 years and 7 months old
French cars don't have the best reputation when it comes to dependability, but this is the only one to feature in Warranty Wise's top 5 rankings.
What goes wrong most often? According to the report, it's engine faults and cylinder head gaskets that tend to cause the most headaches, and cost an average $1090 to repair. While these aren't as expensive to rectify as other models in this list, the relative cost in terms of the vehicle value is still pretty high.
When problems start to pile up: when a car is 10 years and 2 months old
That's a hat-trick of Vauxhalls making the top five least reliable cars, according to Warranty Wise data. That's not good for the brand that was recently bought by the French PSA Group.
The Astra - which is the manufacturer's second best-selling model behind the Corsa in the UK - might be an affordable family hatchback, but keep hold of it for too long and it will become pricey to repair.
The most common warranty claim is for gearbox faults, which cost a staggering $1900 on average to sort out.
When problems start to pile up: when a car is 9 years and 3 months old
Like the Range Rover Sport, the Mercedes C-Class isn't a cheap car. This junior executive saloon is the machine most choose if they don't want a BMW 3 Series but still want the kudos of premium German brand image and a quality interior.
Unfortunately, owners who have paid big fees for one of these cars will be disappointed to know that they do suffer some common problems, not least irritating electrical and sensor faults, which cost an average $703 and $420 respectively to fix.
When problems start to pile up: when a car is 9 years and 5 months old
The iconic Mini has changed somewhat under BMW ownership in recent times, and it's become far more expensive to run as a result.
Long gone are the days of cheap repairs and quick fixes - when something goes wrong with a Mini these days the garage receipts can sometimes be maxi.
All five of the most common claims for repairs are over $378 to fix, with major issues such as clutch, engine and gearbox fixes at the top of the list.
When problems start to pile up: when a car is 1 year and 6 months old
Seat's Ibiza is the Spanish brand's answer to the VW Polo and Skoda Fabia - and uses pretty much all the same underpinnings.
However, it seems to be much less reliable.
So you might think it's inexpensive to repair, given there should be plenty of spare parts kicking around, right? Not exactly.
Warranty Wise have it listed as the eighth most unreliable car based on the frequency of repairs and how much they cost. Topping the list is engine faults, which cost $1588 on average to rectify.
When problems start to pile up: when a car is 9 years and 3 months old
Like the Mini Cooper, the Cinquecento is a retro small car from yesteryear that's now back on the market, be it in a heavily modernised format.
Still, it should represent affordable driving, but the dinky Italian city car has managed to squeeze into the rankings of the models most likely to encounter pricey problems.
Gearbox, suspension and electric faults top the list of issues owners made claims against their used-vehicle warranty for, which cost Warranty Wise an average of $1406, $567 and $681 to put right on average respectively.
When problems start to pile up: when a car is 7 years and 7 months old
This Clio might be a little long in the tooth by today's standards, but there are still plenty of them on the road in the UK today. That might be because drivers are tempted by the low second-hand prices - but they do need to buy with caution.
That's because Warranty Wise data ranks it as the tenth most unreliable used car.
Fortunately, the three most common faults - electrical, ignition and suspension related - are not outrageously expensive to fix (repairs cost from around $238), but gearbox faults are also one of the top five problems and cost and average $1271 to repair.
When problems start to pile up: when a car is 10 years and 7 months old
Now we've hit you with the list of the least dependable motors, what about the ones you can rely on?
Warranty Wise has given us the details of the 10 cars it receives the fewest warranty claims about.
These are the ones to consider buying:
1. Volkswagen Polo
2. Ford Fiesta
3. Ford Focus
4. Ford Transit
5. Audi A3
6. Audi A4
7. Vauxhall Corsa
8. BMW 3 Series
9. Nissan Qashqai
10. BMW 1 Series
Clive Matthew-Wilson, editor of the car review website dogandlemon.com, says the English list of unreliable cars is 'true, but it's not the complete picture'.
"This survey comes from a company that sells mechanical insurance. This survey isn't just a measure of how often a car breaks down; it's also a measure of how much each breakdown costs to fix, So, a car that breaks down all the time, but is cheap to fix, may get a better rating than it deserves."
Matthew-Wilson explains that English car buyers tend to treat their vehicles as short-term consumer items, rather than long-term friends.
"It's common in the UK for a family to buy a new car and keep it for three years, then trade it in on another new car. The New Zealand experience is quite different. Except for old people and a few rich groups, New Zealand families almost always buy second hand cars, and they keep these cars for quite a long time. So, at the Dog & Lemon Guide, we measure reliability over a ten year period, and over several hundred kilometres."
Matthew-Wilson's reliability studies consistently put Toyota and Lexus at the top, followed by Japanese makes such as Mazda and Honda, and Korean makes, such as Hyundai and Kia.
"Virtually every taxi in Auckland is a Toyota. That's not because of some ideological love of Japanese technology, It's because Toyotas tend to keep going far longer than most other makes. From time to time a naive taxi driver will buy a European car, but these cars simply don't last the distance, The English survey tends to show this same sad truth."
- Daily Mail