For those that are interested, I have finally sorted this:
Pair in the normal way.
For outgoing calls, you can use the handset to dial, and the call goes through to handsfree.
For incoming calls, if the handset is used to answer, then the call comes through the handset. If the screen or steering wheel is used, then the call comes through the handsfree.
For caller ID to work - ie come through to the screen in the car, then ensure that BTSAP (Bluetooth SIM Access Profile) is allowed on the handset. The phone number of the incoming call is then displayed on the car screen. If the numebr is in the car phonebook, then the name is displayed. Perfect!!!