Default SMS notification on car radio


I have a car radio (JVC KD-R821BT) which can etablish a bluetooth.
The connection itself is no problem, the phone finds the radio and is pairing without problem. Also phone cals seeme to work well.
The problem is that when I get a new text message (SMS) this should also be displayed on the radio. But it doesn't do it and also my phone is does no sound when it is paired with the radio and I get a SMS. Is there any configuration I missed? Can anyone help me solve my problem?