I have a hands free and use it quite frequently. I do not however use it while in traffic but there isn't much of that around these parts. If 2 cages pass my place in an hour that's a major traffic jam.
I've got an HCB300 Sony Ericsson, cost me £60+£40 for an autoleads interface. Parrot do loads too, but I prefered the little unit the SE one has, it has a little light in the middle to tell you whose connected to it, blue for me, pink for the missus! It mutes the stereo and puts audio to the front speakers. You might be lucky, some cars you don't need the £40 interface for (pugs I think), Renault and BMW mini you will..
