Volkswagen is embroiled in one of the worst auto industry scandals to date — and it's all thanks to a team of researchers at West Virginia University that have been waiting more than a year for the revelations to go global. The group published their findings in spring 2014 detailing how Volkswagen diesel-powered vehicles were emitting far higher emissions levels in standard driving conditions than during testing cycles required and regulated by the Environmental Protection Agency. The team only discovered this by creating a method for testing the emissions levels of a car while it drove down the highway.

The team drove two vehicles, a VW Jetta and VW Passat, up and down the West Coast with huge rigs in the trunk connecting to the exhaust system and found that each emitted more than 20 times the legal limit of nitrogen oxides. Volkswagen admitted to using so-called "defeat devices," software algorithms that artificially lowered emissions output during testing, to bypass US environmental regulations only after the EPA approached the company with West Virginia University's findings.

The testing rig collected gas from the exhaust pipe of VW vehicles

Volkswagen is currently under investigation by both the EPA and the US Justice Department and could suffer damages of up to $18 billion for violating the Clean Air Act, not including any future criminal penalties incurred related to potential corporate misconduct. The company, the largest automaker in the world, said as many as 11 million diesel-powered vehicles are affected and has set aside $7.3 billion to cover the scandal's associated costs. VW CEO Martin Winterkorn resigned earlier today, saying in a statement, "I am shocked by the events of the past few days. Above all, I am stunned that misconduct on such a scale was possible in the Volkswagen Group."