I fixed this by doing the following: In Poweramp, menu->Settings->Headset: * Unchecked "Resume on HEadset Connect". * Unchecked "Resume on BT A2DP Connect". Now, I enter car when the FM radio is on and Poweramp does not automatically launch. If I switch modes in the car to BT Audio, Poweramp launches and plays.
I own a newer Mazda car. My phone is paired with the car. Music plays fine using Poweramp over BT Audio. My issue is as follows: When I enter the car and I have the car audio mode set to FM radio, Poweramp automatically launches and is in the notification area. How do I prevent Poweramp from automatically launching UNTIL I change the mode in my car to BT Audio? Using the previous player, the android/Samsung default player, the music player did not appear in the notification bar until I selected BT Audio mode in my car. I can see no need to have Poweramp sucking battery until I request BT Audio.