I had wondered this since I've owned my car and guessed it was probably around 1300. Ferrari built about 3000 612's from mid-2004 until 2010. So at roughly 500 per year, from mid-2008 until 2010, that would be about 1250, plus the 60 Sessantas built in 2007. Well yesterday I believe I found the answer. I was at Tutto Italiano at Larz Anderson Park in Brookline, MA. At one point a man approached me and asked if that was my 612. He began by telling me he was on the Bose team that designed and developed the Entertainment System for the car. He told me that they built 600 of the units for Ferrari. He made a point of saying that is all that were manufactured and supplied to Ferrari. So if Ferrari used them all, then 60 went into Sessantas and 540 into OTO's. Of course it could be possible Ferrari held a number of units in reserve, so there could be fewer than 540 OTO's built. He told me they built another 1000 that went into Quattroportes. He said those were the only two cars that got those units. Another little interesting story he told me was Bose used a Nissan 300ZX to test the system in. He said the company deemed it too expensive to acquire an actual 612. A couple Ferrari engineers came out during the evaluation and one of the engineers told him the system doesn't matter anyway. He told him only the engine and exhaust sound matters! Obviously I don't have any written documentation of this, and I didn't even get the gentleman's name, but I have no reason to doubt him. We spoke for a while and he clearly had familiarity with the system and the development process. Bose is located not far away. He said he was not with Bose any longer, but went with a company that is working with the Bose active suspension system.