Email from logitech support:
Update: No support on PS4 for Logitech G27:My name is Kenneth V., I understand that you would like assistance with your G27 Racing Wheel.
As for the moment, we currently don't have a definite timeframe on when our racing wheel will be supported on PS4. But yes, we are already on the process of incorporating our gaming wheel to PS4. But mainly we will be focusing on the G27 only and later model.
For future reference your case reference number is 00705258. This will allow us to quickly find the contact history when you need additional help. If we do not receive a reply, your support request will eventually be closed and set to "solved". A survey will be sent to you to gather your feedback.
To contact us by phone or obtain additional information (FAQ's, Forum, Manuals, etc.) please visit support.logitech.com
Logitech Customer Care