Play music through Nokia hands free

Hi, I have a Freelander 2 and the previous owner installed a Nokia hands free, I have just figured out the passcode to pair my iPhone to make calls.
To play music I have to do it through Air Play and my phone connects and shows that its playing the music, but the car stereo just continues to play the radio, is there a button i need to press on the stereo to listen to the using via the hands free?
TIA

You can't play BT music through the car stereo. You need to plug it in via the 3.5mm jack plug, and set the car stereo to AUX.
I'm guessing the BT calls unit is an after market addition, rather than the factory BT option, which presumably wasn't fitted. The factory BT couldn't play BT music either, but the CD can play MP3 CDs.

The call set up is likely to be mono anyway.