BEIJING - Nearly half of complaints filed about auto quality last year were on relatively new vehicles, according to a report released by China's quality watchdog on an auto news website.

The report said complaints on cars with less than 10,000 kilometers on the odometer comprised 45.17 percent of the total.

More than 90 percent were vehicles less than two years old. Vehicles purchased just a month before accounted for 34.4 percent of complaints.

The high figure is the result of two main factors, according to experts - automakers that failed to solve obvious quality problems and consumers who lack knowledge about their new purchase and file unnecessary complaints.

In addition to problems with new vehicles, after-sales service complaints in the past year also increased substantially.

A report from the complaint department for domestic quality supervision shows that vehicle problems also increased in the first month of 2011.

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Many consumers were concerned about real or perceived problems with engines and accelerators on brands ranging from domestic automakers Chery and BYD to giant joint ventures like FAW Volkswagen.

Complaints about engine defects were the most frequent.

Problems with repair is also a growing concern, said the reports, in part because China has no nationwide law governing the field other than ministry-level regulations.

Adding to the uncertainty is confusion about which organization will receive complaint because there is currently no specific government agency in China to handle the issue.

Local media cited experts saying the country should make specific laws to protect the rights of vehicle owners as soon as possible.

The country should also form a professional third-party quality supervision institution for the auto industry to receive complaints from consumers, said experts.