An employee works on an Aston Martin vehicle at the company's factory in Gaydon in the United Kingdom. [Photo/Agencies]

While the Shanghai auto show has offered a stage for many flashy new cars and celebrities, on Friday the spotlight was stolen by furious owners circling the Aston Martin booth with a long banner in protest.

Chinese characters written in black ink on a white banner said: "Rubbish Martin, big repairs for new cars…Deception and passing the buck, Martin played so many tricks… A new Martin car, but five engine repairs."

The story described an Aston Martin owner's experience in Shanghai, according to pictures circulating on microblogging platform Sina Weibo.

Aston Martin Lagonda (China) Automobile Distribution's public letter published on the same day claimed that the car engine had been repaired fully in October last year and now functions normally.

The company "expressed deep regret at the owner's radical actions".

The event came just two days after China Consumers Association's announcement on April 19, the first media day of the auto show.

The association said it has started investigating numerous reports of safety hazards concerning Aston Martin's V8 Vantage, V8 Vantage S and DB11. These models encountered various problems, including gear engagement failures, gears skipping, the engine shutting off during driving and loss of steering control, according to the association.

"Safety hazards exist in the faulty vehicles, but the technicians from the carmakers failed to tackle the problem properly after repeated repairs. The affected cars could have defects in the designing or manufacturing," said the announcement.

Aston Martin China said in a statement that it has solved the problem for several Chinese customers as of April 19 and some other repair works remain in progress.

But the association wrote in its announcement: "The auto company deserves to shoulder the responsibility to inform its customers and cease sales. Actions including alerting and recalling should be taken."

"Aston Martin has been indifferent to the quality of the products," said Yale Zhang, managing director of consulting service Automotive Foresight (Shanghai).

"The carmaker has problems in its attitude toward Chinese customers.

"It shirked its responsibility to take care of its customers," he added.

Zhang said: "Aston Martin is a niche market brand with only about 1,000 customers throughout China," given its recent sales volumes have hovered at just above 200 vehicles a year.

Beijing Martin Trade, a Beijing-based dealer, told China Daily that six out 19 Aston Martin V8 Vantage S vehicles sold between 2012 and 2016 encountered the same engine problems.

Carson Guo, president of Beijing Martin Trade Co, said: "Aston Martin's reply was very cold. It offered no apology, understanding or sympathy, but only regret for the company's actions."

He said he believed if the carmaker treats the problem properly there should be no reason for five rounds of repairs, nor customers' actions at the Shanghai auto show.

Beijing Martin Trade was the dealer that prompted the quality watchdog's probe in 2016.

A document issued in January last year by the General Administration of Quality Supervision, Inspection and Quarantine stated that the Beijing bureau detected signs of design defects in the Aston Martin V8 Vantage S. Guo had received customer feedback on the faulty engine since 2014 and reported the issue to Aston Martin China as soon as possible.

Zhang said: "It is the auto manufacturer who should be responsible for the problems. The quality issue in the powertrain and the core parts are not something can be tackled by the dealers."

He added that: "Aston Martin's weakness in quality control might be a result of frequent senior management replacement, as they lack long-term perspectives".

China's quality watchdog urged a recall of 1,094 Aston Martins across the country in February 2014 after observing safety hazard cases overseas.

The carmaker decided not to recall the affected products in China after filing a recall of about 17,600 Aston Martins in the United States, blaming counterfeit materials bought from a little-known tertiary supplier in China. After the quality issues, Andy Palmer took over Ulrich Bez' seat at the helm of Aston Martin Lagonda in September 2016. Peng Mingshan, also known as Michael, replaced Jenny Zheng as president of Aston Martin Lagonda (China) in February 2015.

Contact the writer through haoyan@chinadaily.com.cn