jlee6412

I think David meant if he had the Bluetooth connected to the headset not to the vehicle. Meaning the phone call would be through a separate BT headset and not through the vehicle's BT Module which would hence have no effect on the vehicle's radio.

I have an 08 S600 with the BT Interface Module connected to the iPhone, if I wanted, I would be able to pair the iPhone with my headset thus eliminating the pairing i originally had with the BT Module in the vehicle and vice versa. By pairing with the headset and not the vehicle's BT module the phone call would have no effect on the vehicle's radio.

Unless i misinterpreted David's question.

Diesel Benz

Yes of course if you don't use any of the car's BT connections, a phone call would not mute the radio. But then you loose all the integration, have to answer and dial calls from the phone.