Auto giants BMW, Daimler, and Volkswagen all broke sales records in the US in the first half of 2012, partly compensating for weakening demand in crisis-stricken Europe.
But even as the car business booms, German firms are also facing their biggest manufacturing problems across the Atlantic. As many as 4.8 million cars had to be recalled in the US because of flaws in the first half of the year, Die Welt newspaper reported on Tuesday.
Citing a report from the Center of Automotive (CoA) at the University of Applied Sciences in Bergisch Gladbach, western Germany, the paper said that BMW had a recall rate of close to 300 percent - in other words, nearly three times as many BMWs had to be brought back to the workshop as were sold. Luxury sports carmaker Porsche also had a worrying recall rate of 130 percent.
In absolute figures, that meant that 458,000 BMWs were recalled, and 21,500 Porsches.
Though the figures only apply to the US market, they are considered a valuable reference point for the global auto industry. "The US market is the world's biggest, and it has the highest safety standards, and so the risk of complaints is the biggest," CoA head Stefan Bratzel told the paper. "What happens in the US can be used to draw conclusions about general trends and other markets."
What makes the figures particularly alarming is that they are way above the US average recall rate of 66 percent - and that in 2011 and 2010 BMW and Porsche were among the firms with lowest US recall rates.
Bratzel puts the quality deficit down to higher turnover and cutting corners in production.
"Maintaining the highest quality despite growing sales is one of the central challenges of the car industry, considering the increasing number of generic parts in cars and the use of automated construction sets," he said.
But a BMW spokesman disputed this analysis. "These recalls are often voluntary," he told Die Welt. "We don't save on quality. Our cars have never been so safe and reliable."