My bluetooth has always been flaky with my car. I have no problems connecting to bluetooth speakers or headphones, but with my car, sometimes the car doesn't recognize the phone at all, and like you said, if I turn the car off (say to get gas), it doesn't always reconnect. Other times it won't connect when I start the car. Turning the car off and restarting lets it reconnect. I've always thought it was just an issue with the car, because it's always been a bit of an issue for me.
I haven't had the issue with audio going back to the beginning. I listen to Audible books each commute, and that would drive me nuts.
03-11-2016 10:27 AM