About 80 percent of auto complaints were for vehicles within the auto warranty period, according to a report by China Association for Quality released on Feb 12. It said complaints for new vehicles used within a month after purchase accounted for 10 percent of the total.

In 2012, the categories that saw the largest increases in the number of complaints were those regarding transmissions, bad service quality, dishonest car salesmen and lack of transparency in after-sales service charges.