Auto dealers are increasingly stuck with cars ordered by potential buyers who back out of payment.
In one case a buyer ordered a VW Golf worth 30,000 euros from Autohaus Hahn + Mayer in Fellbach, but could not afford to pay for the model.
Hans-Peter Mayer, Autohaus Hahn + Mayer managing director, said he knows of at least four similar cases.
Mazda dealer Torsten Treiber, from Ludwigsburg, was left with a Mazda6 worth around 27,000 euros after learning that the potential buyer could not afford to buy the car.
"At the moment this seems to be some sort of national sport," said Mayer.
Mayer said consumers should pay a 15 percent deposit when ordering a car, similar to deposits demanded by furniture and kitchen retailers.
Michael Thiede, from Germany's Toyota dealer association, agreed that increasing numbers of car buyers cannot pay for models they order. He supported the idea of charging a deposit.
Anton Reich, a Ford dealer from Munich, is already charging a deposit when customers order expensive individual extras.
The German dealers association, the ZDK, now plans to a national survey of buyers' paying habits.
"This problem is more acute than people think," said ZDK spokesman Helmut Bluemer warned.