Just got myself a Samsung Galaxy S4 and was wondering if anyone was able to get S Voice to work when they're Prius was not in bluetooth audio? When listening to SAT or FM/AM radio, the audio in S Voice doesn't play in both the car's speakers or the phone's speakers. However it does work when the car is in bluetooth audio. My iPhone 4S never had a problem with this with Siri. The last thing I wanna do is to have to use the Prius's hands-free system.
When you are connected via bluetooth, but not using the bluetooth audio, there should be a setting on the phone for what do you want this device to do. I believe the default for the A2DP profile is just music. Settings->Bluetooth->Device Settings->Checkboxes
It's a sync'd audio connection with the phone which only happens over Bluetooth, hence why you only get the audio in BT source. Apple spoofs a phone call and uses HFP over BT so all audio is HFP. S4 probably sends it only over A2DP would be my guess.
