Dealers are angry that increasing numbers of customers are going to official dealers to test drive cars but then buying vehicles from an importer or over the Internet.
German brand dealers have a fleet of approximately 100,000 vehicles worth around 3 billion euros specifically for test drives, according to the Zentralverband Deutsches Kraftfahrzeuggewerbe (ZDF), the national association for auto traders and repairers in Germany.
Growing model ranges mean dealers have to provide an increasing number of cars for test-drives.
ZDF president Rolf Leuchtenberger said a fee should be introduced to deter non-serious buyers. The fee could then be deducted from the purchase price once a car was ordered.
However, Ferdinand Dudenhoeffer, head of the Center of Automotive Research at the university of Gelsenkirchen, warned that dealers would lose customers if they charged for test-drives.
He said the problem with unofficial imports would only be solved if car prices were harmonized across Europe. He suggested that automakers add a special bonus for test-drives to their margin systems.
Manufacturers also criticized the idea. "This is the wrong way of doing it," said an Opel spokesman.
Kees Jan Boorsma, sales director at Peugeot Germany, warned: "In view of the current market situation, we should not chase away potential customers by charging them for test drives."
Juergen Stackmann, director of marketing at the Ford in Cologne, said: "A test-drive is the last deciding factor on whether a customer buys a car. It should stay free."
Ford in Germany has been offering bonuses to dealers who persuade new customers to try out vehicles - paying 20 euros per test-drive.