I'm looking in to this for someone else, but is anyone familiar with this cars set up? It is possible to retrofit a BT unit with this car?I have an 04 A8L with a broken analog phone. Can anyone help find a blue tooth solution? I have an integrated phone system that came from the factory. Many people are talking about this, but I have yet to get real information as to if it can be done and the costs involved. Any help would be much appreciated.