How many speakers in a Ferrari 575M Maranello
 

Does anyone know how many speakers are in a 575M? From my casual observation there are 4, 1 in the left drivers side door, 1 in the right passenger side door, 1 in the left rear quarter panel, and 1 in the right rear quarter panel.
The reason I ask is because my speakers rear speakers are blown so I thought I would take the opportunity to replace all four (or 6 if there is 6) and install a new bluetooth compatible, iPhone compatible stereo fitted to the original slot.
The car audio specialist who I have been communicating with seems to feel that there are 2 speakers under the dashboard as well, is this true?
Does anyone know?