[Android Auto General] Mad Medik:
Troubleshooting:

I strongly suggest you make sure you have a good quality USB cable and confirm that you are able to connect your phone to your computer and transfer a file (some cables will allow charging but not data transfer).

1. Problem: Bluetooth won't pair, won't connect, etc.

Possible Solution:

It appears that Android Auto will attempt to create a BT profile. So

a) Delete the pairing on your cell phone

b) Delete the pairing on your car head unit

c) Turn OFF bluetooth on your phone

d) Plug your phone into your car's head unit. Depending on your settings, you may need to tell your car to launch Android Auto and you may need to select the device. If so, make sure you are selecting it in Android Auto (NOT Bluetooth pairing). Respond appropriately to any requests for authorization on your phone and car.

This should leave you with a properly paired device and car.

2. Problem: Every time I launch Android Auto, I have to pair my phone again!

Work-around: Once you have a working AA connection between the car and your device, go into the settings in the Android Auto app on your device and turn off the option to "Add new cars to Android Auto."

3. Problem: Android Auto notifies me of a new message but won't read it out loud/but starts to read it and cuts off.

It looks like there is a conflict between Google Now, Android Auto, and the Bluetooth handoff with the car head unit. Kudos to XDA member BuildaWall for discovering that turning off the BT headset option in Google Now fixed it for some people. I did a little more testing and found that forcing Android Auto to make your phone the primary source of audio seems to be the other piece.

UPDATE:I applied the August CM-13 Snapshot and this workaround no longer fixes the problem. I have reheaded it as a possible work-around as it might fix the issue for people on slightly older ROMs

UPDATE Sept 27/2016: I have upgraded to stock Nougat (Android 7). This issue still exists. However, after reading this XDA article, I tested an accessibility option. AA began reading the messages once again.

Possible Work-arounds:

A) Several people reported that their Media volume on their phone was being changed to zero when they plugged into AA. Some also reported that turning USB Debugging OFF fixed this issue. If you don't know what USB debugging is, don't worry about it; you would have to have intentionally turned it on. For volume, tap your volume rocker but then tap the drop down on the pop up volume notification.. It will expand to multiple volume sliders. For simplicity, make sure none are zero.

B) On your phone, go into Google Now, Options, Settings, Voice and then turn off Bluetooth Headset. This was reported to help by some but not didn't help for me.

C) On your car's head unit, in Android Auto, select a music option (I have Spotify and Google Play Music, but I think any audio source app within AA will work). If you don't want to listen to anything, just play and then pause/stop it but you CANNOT go back to the car as a primary source (eg radio or sirusXM).

D) On Nougat (Android 7) go to settings, accessibility, and enable one of the options (I have tested Voice Access, but in theory, activating any accessibility option should reactivate the message reading in AA.

4. Reported with work-around by [MENTION=3188316]ReppinTheSouth[/MENTION] - Android auto either being laggy or flat-out disconnecting

ReppinTheSouth observed this on a Pioneer avh 4100 and a galaxy s4 and reported August 7, 2016

Suggested Work-Around: Clearing the phone's cache periodically seems to help a lot. I also added a swap file which has seemed to help even more.

5. Reported by [MENTION=3188316]ReppinTheSouth[/MENTION] - When driving in maps with voice commands enabled, it will freeze sometimes right when a voice command is about to come on. My GPS will no longer track and my head unit at least an Android auto is completely unresponsive.

I'm not listing this as a work-around, as it doesn't resolve the problem, but is still good to know: [MENTION=3188316]ReppinTheSouth[/MENTION] advises: This only happens when voice commands are enabled & Unplugging and replugging the phone gets the head unit out of its frozen state.

More to come!