Samsung S4 notifications trigger media bluetooth in car

[chicita07]

I just got a Samsung Galaxy S4 three days ago. I paired it with my car's Bluetooth radio/phone. The phone part is working fine, but the problem is with the media. Whenever I get a notification on my phone or if I lock or unlock the screen while it is connected to the Bluetooth in the car, it automatically changes the radio to play the media on the phone. This is really annoying. Is there some setting that I can change on the phone so that it doesn't do this? I had a blackberry before and it never did this so I don't think it is a setting on the car bluetooth/radio.