Bluetooth hands free car system & PBAP

I have successfully paired via bluetooth my iPhone 5 with my cars built in hands free. In my iPhones bluetooth settings I have gone in to the settings for that device and selected to sync contacts. The phonebook in the handsfree system says it is empty so I can't make calls from the hands free system unless I do it from the phone keypad. I am assuming that because I have the option to sync contacts in the bluetooth settings that menas my car has the PBAP function.