The short-term effects of this scandal on VW are already quite dire. On September 21, the company's stock fell over 20 percent at one point on the German exchange, ended down 17.8 percent that day, and have continued to tank. In addition, the Environmental Protection Agency has forced a stop-sale on 2015 and 2016 diesel models with the 2.0 TDI, and the agency has begun analyzing the 3.0-liter V6 TDI in the Audi A6, A7, A8, Q5, Q7, and Porsche Cayenne to look for similar issues. The Justice Department has also started a criminal investigation, and the automaker has instituted its own external probe, as well.
The emissions irregularities were first discovered by researchers at West Virginia University and the International Council on Clean Transportation. The EPA and California Air Resources Board were eventually made aware and launched their own investigations.