The crisis underway at Volkswagen over EPA allegations — and now company admissions — that the firm cheated on emissions tests for its popular TDI diesel engine line has already cost the company’s stock more than a third in value — or some billion — and has caused some to question the company’s viability. It has also now cost the company its CEO: Today, Martin Winterkorn announced his resignation. And the meter is still running. The EPA says penalties could run up to $18 billion, and that would be in addition to individual and class action lawsuits on the way from formerly loyal customers who thought they were buying an environmentally progressive vehicle but now find it is pumping out pollutants far higher than advertised. The big stock price hit followed reports that some 11 million cars worldwide are affected – not just the nearly half million Volkswagen and Audi cars sold in the U.S. since 2009 with a so-called emissions test “defeat device” as first reported.…