[HTC U11  ROMs, Kernels, Recoveries, & Other Develo] Flinny:
I'm nowhere NEAR my car at the moment so I can only go from your logs.

04-23 16:15:07.020 2627 2678 D UsbDeviceManager: entering USB accessory mode: UsbAccessory[mManufacturer=Android, mModel=Android Auto, mDescription=Android Auto, mVersion=1.0, mUri=null, mSerial=null]
04-23 16:15:07.025 2627 2678 I ActivityManager: START u0 {act=android.hardware.usb.action.USB_ACCESSORY_ATTACHED flg=0x11000000 cmp=com.google.android.gms/.car.FirstActivity (has extras)} from uid 1000
04-23 16:15:07.142 30402 30402 D CAR.FIRST: onCreate
04-23 16:15:07.145 30402 30402 D CAR.FIRST: handle intent Intent { act=android.hardware.usb.action.USB_ACCESSORY_ATTACHED flg=0x11000000 cmp=com.google.android.gms/.car.FirstActivity (has extras) }, restart suppressed false
04-23 16:15:07.154 30402 30402 D CAR.SETUP: Package com.google.android.projection.bumblebee not found.
04-23 16:15:07.155 30402 30402 D CAR.SETUP: Package com.google.android.projection.gearhead: installed ver=31581054 minimum required ver=29574900
04-23 16:15:07.185 30402 30402 D CAR.SETUP.SERVICE: Got USB accessory fd: {ParcelFileDescriptor: java.io.FileDescriptor@f41a788}
04-23 16:15:07.186 30402 30402 D CAR.SETUP.SERVICE: Start car connection 1
04-23 16:15:07.197 30402 30402 D CAR.GAL.SECURITY: Using AES/CBC/PKCS5Padding from GmsCore_OpenSSL version 1.0
04-23 16:15:07.210 30402 30402 D CAR.GAL.SECURITY: Loading certificate factory from provider: GmsCore_OpenSSL version 1.0
04-23 16:15:07.225 30402 30402 I CAR.GAL.SECURITY: Successfully initialized SSL context for protocol: TLSv1.2 using provider: GmsCore_OpenSSL
04-23 16:15:07.227 30402 30402 D CAR.GAL.GAL: onChannelOpened() for service null
04-23 16:15:07.227 30402 30402 D CAR.GAL.GAL: skipping onEndPointReady() for endpoint ksa@4df7b07
04-23 16:15:07.227 30402 30402 D CAR.GAL.GAL: startServiceDiscovery

which LOOKS ok...

then later on

04-23 16:15:23.795 2627 2638 I UsbPortManager: ClientCallback: otg_default
04-23 16:15:23.796 2627 2678 I UsbPortManager: USB port changed: port=UsbPort{id=otg_default, supportedModes=dual}, status=UsbPortStatus{connected=false, currentMode=none, currentPowerRole=no-power, currentDataRole=no-data, supportedRoleCombinations=[no-power:no-data]}, canChangeMode=false, canChangePowerRole=false, canChangeDataRole=false
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: IO exception
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: java.io.IOException: read failed: EIO (I/O error)
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: at libcore.io.IoBridge.read(IoBridge.java:538)
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: at java.io.FileInputStream.read(FileInputStream.java:254)
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: at ksm.run(:com.google.android.gms@12529050@12.5.29 (090400-192802242):10)
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: Caused by: android.system.ErrnoException: read failed: EIO (I/O error)
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: at libcore.io.Linux.readBytes(Native Method)
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: at libcore.io.Linux.read(Linux.java:184)
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: at libcore.io.BlockGuardOs.read(BlockGuardOs.java:251)
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: at libcore.io.IoBridge.read(IoBridge.java:528)
04-23 16:15:23.800 30402 5405 D CAR.GAL.GAL: ... 2 more
04-23 16:15:23.801 30402 30402 E CAR.SETUP.SERVICE: 3: io error
04-23 16:15:23.804 30402 30402 D CAR.SETUP.SERVICE: Closing fd: {ParcelFileDescriptor: java.io.FileDescriptor@f41a788}

but yes a log from a working device (anyone?) would help....