iPhone paired audio resumes automatically - how to change

Hello - I've looked through the manual, and can't find an answer to this, so maybe somebody out there can help with this. My wife and I have both our iPhones (6) paired with our bluetooth audio system, and everything works well, except for this one issue.

When we have paused Pandora (played through our phones, not through the Pandora app), or when we have paused a podcast, the audio starts up again under these circumstances:

1. When we raise or lower the volume. (You might ask why are we changing the volume if the audio is paused - it's because we also use our Maps function on our phones for navigation purposes, and occasionally need to adjust the volume on the audio navigation).
2. When we turn off the car, to go into a store, for example, and come back and start the car, the audio resumes automatically.

These problems are not huge, but pretty annoying. We spend a little too much time hitting pause over and over.

Suggestions?

Thanks in advance!