The bonus, valid from September 15th to 22nd is called "Umweltbonus" (Environmental Bonus) and must be fitted before the end of the year. So you can buy it now and get it installed later. The action starts on a day Ford has called "Day of the Champions," on which Ford expects to attract customers to its dealerships. The DPFs are sold at Ford dealers under the Motorcraft brand of accessories.
So far, Ford has sold 12,000 DPFs in Germany. The prices depend on the model. For instance, a filter for a Ford Fiesta costs about 620 EUR and 750 for a Ford Mondeo (before the discounts are applied).