The Maxima and FX guys with the factory bluetooth are not altogether happy. I haven't confimred it myself, but I've heard that the bluetooth has been hard to hear, comes out of one speaker, does not interface with the display (so no caller ID) and has had a limited number of cell phone models that have proven to be compatible. I'd at least wait until the bugs are worked out before undertaking such a big project.
Disclaimer - I do sell the Parrot kits and a Murano interface for Parrot - so I am somewhat biased; but do check out the happiness level with the factory Nissan/Infiniti solution. Howard