VW Whistleblower System is open for employees, business partners (direct suppliers) and customers. It consists of a online reporting channel, a telephone hotline or through an external lawyer (ombudspersons) (Page 6). All disclosures can be made anonymously.

Whistleblowers/anyone that contributes to an investigation are protected by VW, specifically retaliation is not tolerated (Page 6).

Indeed, it is not clear that supply chain workers are covered:

p.6: It enables not only employees, but also business partners and customers around the world to report misconduct by employ-ees any day of the yea