Modified European VW diesels 'undrivable,' say some owners

Most of the Volkswagen and Audi diesel cars sold in the U.S. from 2009 through 2015 are likely to be bought back from their owners, probably leaving fewer than 100,000 on U.S. roads.Roughly 11 million cars with TDI diesel engines were sold by VW Group under multiple brands, and some of those will be modified—in some cases only with software updates.DON'T MISS: Which VW diesels can be fixed, and which can't?