Volkswagen must move quickly to recall and refit car models rigged to pass US emissions tests to limit the long-term impact on its reputation, dealers and consumer protection bodies have said.

"To regain confidence, Volkswagen needs to indemnify any consumers affected by damage," Klaus Mueller, head of the Federation of German Consumer Organisations, said in a statement cited by the Reuters news agency. "The company must either retrofit all affected vehicles or give the affected individuals the right to retrofitting."

VW has set aside EUR6.5bn (US$7.3bn) to help cover the costs of the crisis and said that 11m of its cars could be affected worldwide.

VW said in a statement on some of its websites it could not yet say which models and years of construction were affected, adding it would provide further information as soon as possible. "It goes without saying that we will take full responsibility and cover costs for the necessary arrangements and measures. But this process will take time," VW said.

Italian consumer group Altroconsumo told Reuters it, along with similar organisations in other European countries, was planning to write to Volkswagen demanding clear information on the situation immediately.

Lawyers have already brought class actions on behalf of scores of car owners in the United States, the report added.

Ernst-Robert Nouvertne, who owns VW dealerships in the German town of Solingen, told the news agency how quickly VW refitted affected cars would be critical to reassuring customers, adding that several people had called to ask for information. "Customers are unsettled. It won't just pass us by without problems. Some customers could switch to a petrol car," he said, but noted Volkswagen should be shielded by the loyalty of its customers, at least in its home country.

The report noted that a Sven Rothluebbers wrote on Volkswagen's German Facebook page: "VW must be held fully accountable, but please do not forget that Volkswagen has served Germany with great cars, jobs, social commitment and more the past 70 years!"

Meanwhile, market research company YouGov [click on 'Press Release' below – ed] said it had recorded a big hit to the VW brand in the United States and Britain where VW has tumbled into the lowest position among 34 brands.

Steve Young, managing director of auto industry research firm ICDP, told Reuters the experience of previous car recalls by other brands showed it could actually bring dealerships more business.

Young noted how Toyota had recalled millions of vehicles from 2009 due to some customers' complaints that their cars were unintentionally accelerating. "It depends on how well they manage the process… in the case of the Toyota recall in the US, Toyota dealers were able to reconnect with customers," he said. "If the dealer handles it well, they could help customers use the compensation to switch into petrol and sell their fixed diesel model to somebody who knows what they are getting."

Ansgar Klein, head of the German Association of Independent Dealerships, told Reuters he did not expect a lasting impact.

"The Golf has not got worse. I don't think prices will fall as a result," he said. "Most drivers care more about fuel consumption than emissions. The scandal has not affected trust in VW cars, although trust in the company has suffered."