Bluetooth autoplay start playing from youtube instead of music player

[Android Central Question]

Sometimes, when I get bored of the programs on my car radio, I'll often switch to the media player to play music from my android phone. However, it often attempts to play from YouTube, even when the phone is disconnected from the net; in the car display, the URL of the video shows up, and there is absolutely no sound comming out. Fixing this on my phone while driving is not somthing I or anyone else should do (unless you have a passenger to do it for you).

How can I prevent my phone from autoplay from YouTube, and only autoplay from the music player.