Chevrolet MyLink Audio - OnStar

Does any one know where I can get answers for MyLink Audio connection to BlueTooth Music on My iPod Playlist. I have a new Chevy Sonic and I just want to ride with the music - I had it once but it seems like after you shut off the car you loose the link and have to start all over.

I've heard so much abour the OnStar - but I just want to play my playlist on the radio!

Any Help?