Bluetooth Issues with Lollipop 5.0.1

Hopefully this will solve my similar problems.

1. Unpair both devices (remove the car from the phone; vice versa)2. Make sure you turned off your bluetooth3. Go to: Settings -> Applications -> Application Manager -> All4. Clear Cache first then Clear Data: “Bluetooth”, “Bluetooth Test”5. Enable bluetooth & pair again with your car6. IMMEDIATELY disconnect (you can do it from either way; car or bluetooth).. but keep the bluetooth turned ON7. Download latest “Bluetooth File Transfer” application from Google Play8. Open it and switch to the second tab (“bluetooth icon”)9. Select your car and do the following three things one by one (until they complete!!!): File Transfer Profile (FTP), Object Push Profile (OPP), Phone Book Access Profile (PBAP)PLEASE NOTE: each of these steps may take 5-10 minutes and will FAIL for sure (a “STOP” sign will pop up in the application after it completed the action partially. Be patience and wait until that. If you did all three steps you can close the “Bluetooth File Transfer” app and move on Step 10.)10. Go to Settings -> Security -> Trust agents -> Smart Lock (Google): ON11. (you may need to leave and re-enter to Settings to see it) Smart Lock -> Trusted devices -> Bluetooth -> your car

Source: Bluetooth Issues with Lollipop 5.0.1 – Android Forums at AndroidCentral.com