for some reason when you get a new iPhone Apple automatically names the device with your name and an apostrophe like Eric's iPhone. Some connected devices like Bluetooth system's, Wi-Fi routers and VPNs don't like the apostrophe. Go to iPhone settings, General, About, and change your device name to something without the apostrophe or any other characters other than letters and numbers such as Erics iPhone without the apostrophe. Now delete your iphone from your Bluetooth system in your vehicle and turn off your Bluetooth on your phone but first delete any Bluetooth device profiles on your iphone and then turn it back on and reconnect to your vehicle Bluetooth system. Before I did this my new iPhone 6+ with iOS 8.02 was able to play music and other sound from apps through my Bluetooth system in my Nissan Altima 2015 however none of my cellular phone call audio was coming through the Bluetooth system even though it appeared that it was connected correctly. Basically the phone call was going on in the background somewhere but no one could hear me and I couldn't hear them. Now that I followed the steps and renamed my device without the apostrophe everything is working perfectly. I didn't have to reset any of the network settings or do any type of restore on my iPhone.
