Why are more and more car companies teaming up?

When BMW and Daimler announced a €1bn (£880m) partnership last week to develop a suite of “mobility services” together, it was a clear sign of how the auto industry had changed. For one thing, the German giants – who plan to work on driverless vehicles, ride-hailing and pay-per-use cars together – are normally fierce rivals who would never dream of teaming up.