It’s not unusual today for rival carmakers to work together in developing new technologies that will eventually be shared by both companies. One of the most significant partnerships in recent history was the co-development of hybrid technology by the then DaimlerChrysler, BMW and General Motors.

The next major joint-venture could be between Europe's second-biggest volume car maker, PSA/Peugeot-Citroen, and the world's two largest luxury labels, BMW and Mercedes-Benz. Peugeot-Citroen CEO Christian Streiff has told Germany’s Die Zeit that such a deal was possible and that he wouldn’t exclude it.

Peugeot-Citroen has already co-developed a petrol engine with BMW, whose CEO Norbert Reithofer has previously admitted to being open to developing engines with arch rival Mercedes. A new engine plant can cost upwards of $1 billion so forming a partnership will allow both sides to spread costs and share any risk.