As Manfred Bischoff steps down after 14 years as chairman of Daimler AG's Supervisory Board, his successor Bernd Pischetsrieder will inevitably face fresh challenges as he steers the company through the 2020s. So what can we expect when it comes to what matters most of all - the cars that must both continuously reinvent the Mercedes-Benz name and bring in the cash to fund their even higher tech replacements?