Bluetooth turns off all by itself
We have two new iPhone 6 units.
Mine doesn't do it but my wife's fails to sync with her Lincoln "Sync" and I find that the Bluetooth has turned off.
She is not technically inclined and will default to picking up her phone while driving.
She did not turn the Bluetooth off.
We use the most recent iOS update (8.1.3)
I found one entry in the discussions, it was dated 2008, referenced iOS 2.1. There were no answers
iPhone 6, iOS 8.1.3