I'm not sure if anyone else has had this problem in the past, but I was using the bluetooth in my Clio for a good few months before someone from a different forum (before I joined this forum) helped me out. I have the optional bluetooth in my car and it all worked fine apart from I couldn't end phone calls. The instructions say it is the source down button but that doesn't work. Then I found out that the scroll wheel has another button. You pull it towards you! That ends the phone call and also goes back. So if anyone has had this problem, now you know what to do! The button also changes the radio between present, list and the other one!
