Good afternoon scottmasonky,
Welcome to the Apple Support Communities!
I understand when you adjust the volume on your iPhone or from the controls in your 2015 Toyota Tacoma, that the Music app opens and plays over whatever you were listening to. I know what you are talking about, because this has happened to me when I rent a car and connect my iPhone via Bluetooth.
Which iPhone do you have, and running what operating system? iOS 13.2 was released October 28, so the first thing I would suggest is to make sure your iPhone is updated. Then, check to see if there is a firmware or software update for your truck, and restart both.
Update your iPhone, iPad, or iPod touch
The feature that you are talking about is called Auto-Play. When automobiles are connected to the iPhone via Bluetooth, music will automatically start playing from the iPhone through the Bluetooth speakers when you get into the vehicle or change a setting in the stereo system.
Here are some ways you can turn off Auto-Play:
- Check the manual for your vehicle to see if there is an option to turn off the auto-play feature in the Bluetooth or audio settings.
- Quit the Music app on your iPhone before you get in your vehicle - How to force an app to close on your iPhone, iPad, or iPod touch.
- Disable cellular usage for the Music App on your iPhone - Tap Settings > Cellular and turn the switch to off for Music. Do the same for any other music apps (ie. Pandora, etc.) that might be trying to automatically connect to your iPhone.
If the issue persists, try removing the iPhone from the car stereo and pairing it again.
Try connecting your iPhone directly to USB to test as well.
Connect Bluetooth devices to iPhone - iPhone User Guide
If your iPhone, iPad, or iPod doesn't connect to or work in your car
Please reply to this thread and let me know if you are able to turn Auto-Play off using one of these methods so that you can enjoy your podcasts.
Take care.
