German carmakers are coming under pressure in the wake of a high-profile domestic debate about diesel engines' impact on air quality.
Brisk demand for diesels has been a bright spot for the industry at a time when overall car sales are generally weak in Germany, but health-conscious Germans have been swept up by concerns that diesels may make people ill if the cars have no filters to trap soot.
"We have to take this topic seriously," Volkswagen marketing chief Georg Flandorfer said last week.
"Dealers have told me there is a lot of customer interest in having particle filters retro-fitted (added after production). We should concentrate on retro-fit solutions for now because that does the most for the environment."
Other German car-makers are also rushing to offer particulate filters as standard or optional equipment. Mercedes, for instance, now offers 20 diesel models with maintenance-free filters, more than any other carmaker.
German garages association ZDK estimate that dealers are sitting on inventory of more than 100,000 diesel cars which did not have filters and had thus lost up to €1,000 in value over the past two weeks.
A spokesman for the German car industry association, VDA, Eckehart Rotter, said: "We have to watch out that there is not an impact because everyone talks about it so long that it becomes a self-fulfilling prophecy," he said.
Diesel cars accounted for 44.5 per cent of new registrations in the first quarter in Germany, up 3.5 points. Overall car sales in Germany fell 1.9 percent in the quarter.
The German government plans legislation to speed the introduction of diesel engine particle filters after two German cities breached new EU air pollution limits only weeks after they came into force at the start of the year.
The news that Munich and Stuttgart had both gone over the EU limits, with several other German cities on the brink of following, has sparked widespread discussion over airborne particle pollution and its ill effects on people's health. Most of the particles occur naturally, but they also come from industrial emissions and from tyres as they wear down.
In Ireland last year one in every five new cars registered was powered by a diesel unit, the highest ratio in 15 years. In January and February this year more than 9,280 diesel cars were licensed for the first time, more than 26 per cent of the total.
Cyril McHugh, chief executive of the Society of the Irish Motor Industry (SIMI), said whether or not a new diesel car has a filter still very much depends on the manufacturer. "It's the new technology but it's coming in, there's no doubt about that."
However, he said diesel car sales in Ireland were unlikely to be greatly affected by the debate because "so little of our car population is diesel. The British and ourselves are traditionally on the low side."
