Our coverage of an address to 20,000 Volkswagen employees at Wolfsburg this week, during which VW Group CEO Matthias Müller appealed for unity as the company seeks to recover from its current crisis, attracted a lot of reader interest. As did the departure of VW's US division's CEO, Michael Horn. He was expected by some observers to emerge as a management casualty at VW as the dieselgate crisis unfolded in the US last year but appeared to weather the initial storm and stayed in position.