Ford (Microsoft) Sync and iPhone 3.0 Bluetooth - how do I disable it?

I have a 3G iPhone with the 3.0 software and drive a Ford with the Microsoft Sync package (bluetooth and USB). Before the 3.0 software, the iPod on the iPhone played through USB and the phone worked over bluetooth just fine.

Now the iPhone starts playing music over Bluetooth media streaming once I start the car, it's a random track and I have no control over what is selected.

I want to disable the Bluetooth streaming without disabling Bluetooth entirely. Any suggestions?