Martin Winterkorn

Volkswagen?s top-of-the-range automaker Audi said on Sept. 28 that 2.1 million of its diesel cars worldwide are fitted with the sophisticated software enabling them to cheat emission tests.

In Germany alone, 577,000 vehicles were affected and 13,000 in the United States, an Audi spokesman said. In western Europe as a whole, the number was 1.42 million.     

Norway's economic crimes unit said on Sept.25 it had opened a fraud probe into German carmaker VW to see if cars sold in Norway had been equipped with pollution test cheating software.

Volkswagen chief executive Martin Winterkorn resigned on Sept.23 over a pollution cheating scandal that has sparked a US criminal investigation and worldwide legal action with unfathomable financial consequences for the auto giant.

Volkswagen's pollution cheating scandal escalated dramatically when the automaker revealed 11 million of its cars worldwide could be affected, wiping a third off the company's market value and threatening to topple its chief executive.     

Shares in German auto giant Volkswagen fell more than 13 percent on the Frankfurt stock exchange on Sept. 21 after it emerged some of its diesel cars in the United States had been fitted with software that gave false emissions data.

In the first few minutes of trading, VW shares fell by as much as 13.23 percent to 140 euros in a slightly lower market.    

It could be the battle of the titans. Auto giants at the Geneva Motor Show say they welcome the potential move of Silicon Valley players into their sector but experts warn of major disruptions.

Google has long made headlines with its plans for a self-driving car, but Apple is now also reportedly readying for a plunge into the industry to begin developing an electric car.