Moto X (2014) :: 5.1 Keeps Dropping BT Connection With Car Radio

This phone (stock, non rooted) was working with BT fine under 5.01and Kit Kat before it for mostly calls. I know it is the phone because I have tested it now in three different cars, my 2014 Prius, a new Chrysler and Ford. It exhibits the same behavior. Pairing is not a problem. If the screen in on when I enter the car the connection is made. When the screen dims (sleeps) the connection drops shortly thereafter. If I swipe and get the screen back on I can manually re-connect through the car's radio. If I enter the car with the phone in my holster, likely asleep, it will not connect.

Keeping the screen from sleeping appears to "remedy" this issue but that is hardly an option in terms of battery life. Normally I keep the phone in a holster and never had this issue. I have tried every remedy on the Internet. I am using safe lock and have the radio as a trusted device. I have removed safe lock and the same issue ensues. I have unpaired, cleared cache, re-paired etc.

Last night I hooked up the phone to my Garmin Nuvi via BT. No disconnect issues.