It installed perfectly and was plug and play in 2004 BMW X5 with BMW assist configured, which had a microphone pre-installed. The dealer was wrong there is and upgrade path to retrofit Bluetooth into the post 2003 models. One thing to bear in mind is that while the phone address book will synch and display, the BMW phonebook must been input manually using voice input command that are not well documented. You can find the BMW communication manual on-line, which documents all of the voice commands.