How can I have my BT headset and smart watch stay connected when I connect my phone to Android Auto

Every time I plug my phone into my Kenwood car stereo my phone disconnects my Bt headset and my smart watch. I prefer to continue taking my calls with my headset, especially when someone else is in the car with me. I am able to go back into the BT settings in my phone and re-connect with the smart watch, but I can't do the same with the headset. Even though I can reconnect the watch I would prefer to not have to do this every time I get in the car. Is there a way to prioritize my BT devices or allow all of them to connect at the same time?

What phone do you have?

It's an S7 Edge