VW, Porsche, Audi dieselgate vehicle owners: what you should do

Today the EPA issued a new set of notifications for vehicles made by Volkswagen, Porsche, and Audi. The vehicles in question join the growing number of automobiles with "defeat devices" aimed at allowing more nitrogen oxide (NOx) to be emitted from the vehicle than is legal inside the United States. Defeat devices were discovered on 3.0 liter diesel engine versions …