A shocking three quarters of the used cars inspected in the UK by the RAC have faults that would cause the car to fail an MOT (NCT) and a further one in three have potentially dangerous or illegal faults, according to the motoring organisation.

For those looking to buy a used car, especially Irish buyers thinking of buying in the UK, this should be a stark warning, as the financial cost of fixing a faulty second hand car could prove to be a heavy burden - let alone the danger of driving a car that is unroadworthy.

The most common faults found by RAC engineers were worn or damaged tyres, many of which were illegal. 44 per cent had faulty steering and/or suspension, making driving risky, particularly in poor weather conditions. A further 42 per cent had fluid leakages, 39 per cent had corroded or worn brake discs and countless more had damaged exteriors, such as cracked windows and chipped paintwork.

The results highlight the reality that driving a car with a fault, no matter how small, could potentially increase the likelihood of having an accident or emergency breakdown. The cost both emotionally and financially can be significant. It is vital that used car buyers know what to look for, both under the bonnet and externally. This is because more often than not, dangerous faults can only easily be spotted by a trained eye.

Cars are designed to react in a certain way in a crash that ensures the occupants are protected as much as possible. Any defects (damage or excessive wear) that affect the structural integrity of the vehicle will impair the cars ability to protect the passengers inside. Drivers of second hand cars are never as safe as they think they are.

To help motorists avoid the pitfalls of buying used cars, these are five useful used car buyer tips:

• Always check the car's log book or registration document to validate ownership, accuracy of age and mileage. Don't rely on the NCT or MOT if buying in England or N. Ireland, as evidence of a car's condition. In addition, an RAC Car Data Check will give you the previous history of the vehicle and tell you if it is registered as stolen, has been written off, or is still on finance.
• View the car in good weather conditions and in daylight.
• Test drive the car on a range of roads for at least 10 minutes.
• If you haven't got a mechanically minded friend or family member that can view the car with you, get at a full vehicle inspection which will help identify potential expensive mechanical problems and major accident repair. The resulting report can help you negotiate getting repairs made, worn items replaced or money knocked off the price. With the average value of repairs required exceeding €200 - the report can pay for itself almost instantly.
• Too good to be true? It probably is. Don't get emotionally attached to the car until you've had it properly checked out.