"Volkswagen was reportedly warned about rigging emissions tests on its vehicles years ago, not only by one of its suppliers but also the German car giant's own engineers.
According to the Frankfurter Allgemeine Sonntagszeitung newspaper, VW's technicians flagged up concerns about the engine management software the company was using in its motors back in 2011.
It was also reported today that VW had been cautioned eight years ago not to rig the tests by its software supplier Bosch. According to Bild am Sonntag, Bosch had written to VW in 2007.
The cheatware detects when a motor undergoes emissions testing, and then fudges the engine output to pass the examination by cutting performance to meet emissions standards for nitrogen oxide."