If this spy video is anything to go by, we'd say almost definitely so. The footage shot at the company's private Fiorano test track in Maranello shows a California test mule lapping the circuit, but the sound is what gives it away: the prototype is emitting a pronounced turbo whine.
Of course, Ferrari engineers could be using the California to test out the turbocharged engines it is said to be developing for Maserati. Or the automaker could be preparing to use them in its own sports cars as well. The final outcome remains a mystery, but for now you can watch the video clip below and see - or more importantly, listen - for yourselves.