Buying guides

Low-mileage cars are worth more than high-mileage ones, which is why some vendors reduce the displayed mileage on the cars they're selling – it'a a practice known as clocking. A car's mileage display is known as its odometer; many modern ones are digital so they're even easier to clock.

However, traditional analogue odometers have to be removed for the mileage to be wound back, so if the car has one of these, look for evidence that the dashboard has been tampered with. Damaged screw heads is one way of looking, or scratches in the paint around the screws.

Whatever type of odometer is fitted, check that the wear and tear on the car fits in with the stated mileage. If the pedal rubbers and steering wheel are worn smooth, the car isn't a low-mileage one. Ask for the car's service history and previous MoTs; they'll all have the mileage on, so make sure it goes up steadily and doesn't suddenly drop.

It has also been known for a car's mileage to be reduced for the selling process, but once you've snapped it up, the odometer then mysteriously reverts to its true reading. That's why you need to check the reading doesn't suddenly shoot up between buying the car and collecting it.

When you buy a car you're reliant on its identity being genuine. However, it's possible for a car to be stolen, then given the identity of a written off car. While this should still set alarm bells ringing, at least the car is legal, if not necessarily desirable, when it's merely recorded as previously being a write-off.

You can guard against buying a ringer by inspecting the registration document closely and ensuring that the chassis and engine numbers on it match those on the car you're viewing. Make sure you're looking at the car on the seller's drive – at the address on the registration document. Those involved in ringing tend to be part of organised gangs that vanish without trace once you've paid for the car and taken it away.

If you do buy a ringer, don't try to sell it on as you'll be liable to prosecution. Tell the police and in the case of a purchase from a dealer, also tell Trading Standards. It's essential that you don't get taken in by this scam, because if you do you'll lose the car (which belongs to the insurance company) as well as your money.

If you're not careful, you could end up getting two cars for the price of one when you next buy a used car. Unfortunately, to be more accurate, you're getting two halves for the price of one whole, because you could end up buying a cut and shut.

Such vehicles are the result of two written off cars being used to create one apparently good vehicle. It works by welding the front half of a rear-ended car to the back half of a car that's been in a serious front-end smash. The cars are literally cut up then welded together to create a car that looks straight. However, while the car may look fine, it's a rolling death trap that'll disintegrate in the slightest impact.

To make sure you don't get taken in by this scam, you need to look closely along the top of the windscreen as well as underneath the seats. It won't take much to see the join from underneath, unless copious quantities of underseal have been plastered everywhere. Also look out for badly mismatched paint as well as overspray on the glass and trim; these suggest the car has been repainted at some point. Mismatched trim inside the car is another giveaway.