Volkswagen is already on the hook for $14.7 billion after it settled a case against California regulators and the owners of 475,000 vehicles compromised by the company's "defeat device." The company plans to buy back these cars and otherwise compensate owners, and it promises to devote billions to enhancing its zero-emission infrastructure.

Volkswagen admitted in late 2015 that it installed secret software designed to cheat emissions tests on as many as 11 million of its diesel vehicles. The defeat device made some of Volkswagen's 2.0- and 3.0-liter vehicles emit fewer harmful gases during testing, but in reality, the cars produced up to 35 times the legal level of nitrogen oxide, which is known to cause respiratory problems.

This week, the FBI reportedly charged Volkswagen's former regulatory compliance officer Oliver Schmidt with conspiracy to defraud the US. Former Volkswagen CEO Martin Winterkorn resigned shortly after news of the defeat device broke in 2015, and the company has calculated the cost of its diesel emissions scandal to be $18.2 billion.

Today's settlement requires Volkswagen to cooperate in an ongoing investigation into the defeat device and any potential cover-up. The AP says six Volkswagen supervisors have been indicted over accusations that they lied to regulators or destroyed evidence related to the emissions scandal.