The Volkswagen emissions scandal has moved with lighting speed, so fast that it hasn't even been a week and already the CEO of the Volkswagen Group is stepping down. Martin Winterkorn announced his resignation via a press release, one day after issuing a public apology. For those who don't follow the auto industry, know that a CEO resigning a week after a scandal broke is the exception, not the norm. His resignation was brief and in it he claimed no knowledge of the "defeat device" designed to cheat emissions tests.

"As CEO I accept responsibility for the irregularities that have been found in diesel engines and have therefore requested the Supervisory Board to agree on terminating my function as CEO of the Volkswagen Group. I am doing this in the interests of the company even though I am not aware of any wrong doing on my part." Either Winterkorn knows what's up and is bailing out early or he genuinely had no idea that someone below him pulled such a boneheaded move. Regardless he is CEO and as such gets credit for the company's success and its shortcomings and scandals. Of course this isn't the end of the saga. Oh no, there is still plenty more to come.

The EPA is now investigating the 3.0-liter TDI V6 diesel engine, found in numerous Audis and the Porsche Cayenne. There's also still the matter of the fine VW will need to pay, which could be up to $18 billion (so far). The CEO may be gone but this story is just starting, so keep your popcorn handy.