Hank has a 2007 Nissan Infinity and it has Bluetooth support with its stereo, but it won't play music. Leo says that it may be that the audio connection is secondary to his mobile phone connection. There are two profiles with Bluetooth — one is the headset profile for talking on the phone, and the other is a higher quality A2DP profile for music. It could be that if the stereo doesn't support A2DP, it won't be able to connect for music. If there's an aux jack, he can try using a Bluetooth connector that way. Or he could even just use a wire.
Hank can also buy a Bluetooth radio transmitter that he can tune in to with the car's radio, like this Bluetooth Car Kit FM Transmitter MP3 Player Wireless Radio Adapter USB Charger.