The number of complaints about the used car sector rose by 18% in the first six months of the year compared with the same period in 2009, according to new Office of Fair Trading statistics.
Used cars topped the list of complaints with Consumer Direct recording 38,138 instances.
However, the number of complaints had fallen sharply from the 50,790 complaints that were recorded in the final six months of 2009.
Mobile phones came second with 22,612 complaints and televisions came third with 22,138.
The study found that many motorists ended up fixing problems with their new purchase themselves, at an estimated average cost of £425, when in fact they were the dealer's obligation to correct.
Consumer Direct operations manager, Michele Shambrook, said: "Dealers have a responsibility to sell cars that are of satisfactory quality.
"This will vary depending on issues including the vehicle's age and mileage, but as the vast majority of all second-hand car faults come to light in the first three months, they will often be the dealer's responsibility to fix."
Paul Williams, Retail Motor Industry (RMI) chairman, said: “It’s really important that people are well informed when purchasing a used car, and we fully support the OFT’s campaign to raise awareness of consumers rights, which will lead to elevated levels of consumer confidence.”
The RMI provides a conciliation and arbitration service for consumers who have purchased a car through an RMI member garage.
Williams said: “If a consumer has purchased a car from an RMI member garage, and is not entirely satisfied, then we can assist with the conciliation process.
“Should conciliation not resolve the issue, then we can intervene and provide an arbitration service, which is free of charge to the consumer, should the garage be found to be at fault.”
The RMI are currently working with manufacturers, franchised dealers, independent garages, the police and local authorities to raise the standard of used car sales practices in the UK.
The OFT said that although most car dealers are reputable it advised people buying a used car take the following precautions:
- What mechanical history and mileage checks have they done on the car you want to buy?
- How many former owners has the car had and is the full service history available?
- Has the car been modified from its original specification?
- Is the car ex-hire or similar?
- Ask for important information and answers to your questions to be put in writing before you buy so you have proof of claims - don't just rely on verbal claims or promises by the seller.
- Find out about the dealer's customer complaint procedures and whether they are signed up to a code of practice - if a problem does arise after the sale you need to know who to contact.
- Remember that if you buy a car from a private seller or an auction, you may pay less but you will have fewer legal rights than when buying from a dealer.