Okay, I think I've figured it out. It definitely is the google play services update 7.3.29 on a N6 running Android 5.0.1. I can take out my SIM and block google play through my home firewalls then downgrade to 7.0.99 and it works flawlessly. I then tried to manually update to Android 5.1.0 with google play services 7.3.29 and it also works flawlessly. So my recommendation is to manually apply the 5.1 update.
To verify my findings I tried to go back to 5.0.1 and once 7.3.29 services come down it no longer works. And went back to 5.1 and it works again. Definitely an issue with 5.0.1 and google play services 7.3.29 combination.
All of this testing was done with factory images, the only non factory application installed was android auto. all partitions on the device were formatted prior to applying system images.