Citroen's Numero 9 plug-in hybrid concept is an all-but-ready-for-production precursor to the French automaker's future flagship, which is expected to be called DS9. The Numero 9 concept (equipped with a 221-horsepower 1.6-liter direct-injection gasoline engine - 0-60 acceleration in less than 5.4) will be unveiled later this month at the Beijing auto show.