The sharp increase in the number of cars recalled in the United States over safety issues and defects points to a worrying trend, a German automotive think-tank has warned.
More than 20.5 million vehicles were recalled in the US during 2013 - five million more than in the previous year, said the study conducted by the Centre of Automotive Management (CAM) in Bergisch Gladbach.
Most of the recalls were caused by electronics and safety glitches, such as defective ignition and airbag faults, said Stefan Bratz, the author of the study. Drive-train problems including the risk of engine fires ranked second.
The risk of recalls is set to rise, since many manufacturers base a range of multiple models on the same modular platform.
Their aim is cut costs and to make production leaner, but this practice could rebound on carmakers since a fault in one common component is likely to affect many different models that use the part.
This in turn leads to much more expensive recall actions. In one campaign, 2.7 million Hyundai and Kia models were recalled over a potentially faulty switch and a loose headliner which could affect airbag deployment.
Hyundai-Kia tops the US recall stats with a recall quota of 263 per cent of new cars sold.
Second place goes to Fiat-Chrysler followed by Toyota. The fourth slot goes to BMW. Recalls by Europe's biggest carmaker Volkswagen rated below average last year, despite a small rise in recall numbers. Of the carmakers examined, Daimler recalled the lowest number of cars.
The recall quota refers to the ratio of recalls to cars produced. The figure can be higher than 100 per cent, since a recall may span cars produced over a period of several years.
Recall requirements in the United States are particularly strict and the risk of companies being taken to court over defects is greater.
This makes the US market a good indicator of recall activity.
A US congressional committee recently said it is investigating perceptions of delay in General Motors' recent recall of 1.6 million cars over faulty ignition switches.