More people have filed an official complaint about the dealer used cars this year than any other type of merchant, the figures showed.
Nationally, more than 56,000 people complain direct to the consumer, on a used car from January until the end of September 2011. It is comparable to about 48,000 complaints about home maintenance and improvements, more than 36,200 about furniture, and nearly 35,000 about telecommunications.
Complaints about a used car, 70% of the faults with the car, more than 13% is about misleading claims or omissions by sellers, and nearly 7% of substandard service.
OFT study published last year found that consumers were left out of pocket for an average of £ 425 each because they have to correct the mistakes of unresolved which dealer liability to repair.
"We continue to receive a large number of complaints which are often due to some traders who refused to deal with legitimate complaints or provide appropriate compensation," said Michele Shambrook from consumer direct. "Traders who fail to treat customers fairly or sell the broken car could face legal action."