Before I updated my iPhone 3GS to iOS 4.1, I could use Voice Control when the iPhone was connected via Bluetooth. I'd hold the home button, Voice Control would come on, the double-beep would play through the iPhone speaker, I'd say "Call Johnny Appleseed. Home.", Voice Control would say "Calling Johnny Appleseed. Home." through the iPhone speaker, and the call would happen through the car audio system. Now when I press and hold the home button, Voice Control comes on but the double-beep plays through the car audio system. I say "Call Johnny Appleseed. Home.", Voice Control says "Calling Johnny Appleseed. Home." through the car audio system, then the Prius display shows "Call Disconnected" and no call is made. Has anyone else had this problem? Is there a fix?
For me, the voice control comes through the car speaker as you describe. But then the call connects. I think it is better than before. I have an iPhone 4 with iOS 4.1.
Voice Control works with BT for me. For iPod control to work, you have to use BT audio. The iPhone can't be connected to the car via USB (because it locks out all music control from the phone) I don't think it interferes with voice dialing.
