Customer issues regarding independent used car dealerships topped complaints to the Citizens Advice Bureau between April and June 2012.
During that period there were 12,000 complaints about second-hand cars bought from independent dealerships. This amounted to 8% of all complaints made in that period.
Two thirds of the used car complaints were to do with the customer's car being faulty, while one in 10 complainants felt they were misled by a salesperson.
Local CAB offices in England and Wales also dealt with more than 3500 cases of second-hand cars either being unsafe or not working properly.