[Paid Software Announcement and Discussion] LLStarks:
If anyone is interested, here's the Honda vendor app manifest that comes on models that use Mitsubishi-built headunits. I can also provide an apk and odex if anyone wants to take a whack at reverse-engineering it.

I'm hoping there's a way to fake a USB connection or otherwise trick the headunit into acting as its own slave.

<?xml version="1.0" encoding="UTF-8"?><manifest versionCode="1" versionName="1.0" package="com.mitsubishielectric.ada.app.androidauto">
<uses-sdk minSdkVersion="17" targetSdkVersion="17"/>
<uses-permission name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission name="android.permission.RECORD_AUDIO"/>
<uses-permission name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission name="android.permission.BLUETOOTH"/>
<uses-permission name="android.permission.GET_TASKS"/>
<uses-permission name="android.permission.READ_LOGS"/>
<uses-permission name="com.mitsubishielectric.ada.permission.VEHICLE_RW"/>
<uses-permission name="android.permission.MANAGE_USB"/>
<application label="Android Auto" name="com.mitsubishielectric.ada.app.androidauto.AndroidAutoApplication" persistent="true" allowBackup="true" supportsRtl="true">
<activity theme="Theme.Fullscreen" label="Android Auto" name="com.mitsubishielectric.ada.app.androidauto.ui.MainActivity" launchMode="3" screenOrientation="0" windowSoftInputMode="0x2">
<intent-filter>
<action name="android.intent.action.MAIN"/>
</intent-filter>
</activity>
<activity theme="Theme.Transparent" name="com.mitsubishielectric.ada.app.androidauto.ui.DeviceListActivity" exported="true" launchMode="1" screenOrientation="0" windowSoftInputMode="0x2"/>
<service name="com.mitsubishielectric.ada.app.androidauto.AndroidAutoService" permission="com.mitsubishielectric.ada.permission.VEHICLE_RW">
<intent-filter>
<action name="com.mitsubishielectric.ada.app.androidauto.IAndroidAutoService"/>
</intent-filter>
<intent-filter>
<action name="com.mitsubishielectric.ada.app.androidauto.IAndroidAutoControl"/>
</intent-filter>
</service>
<service name="com.mitsubishielectric.ada.app.androidauto.LogMonitorService" permission="com.mitsubishielectric.ada.permission.VEHICLE_RW" process=":logoutprocess">
<intent-filter>
<action name="com.mitsubishielectric.ada.app.androidauto.ILogMonitorService"/>
</intent-filter>
</service>
<uses-library name="com.mitsubishielectric.ada.appservice.avapservice.lib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.unitinfomanager.lib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.appmanagerservice.lib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.vehicleinfomanager.lib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.strgsw.lib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.hft.lib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.navigation.lib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.externaldisplay.lib"/>
<uses-library name="com.mitsubishielectric.ada.app.systeminfoservice.lib"/>
<uses-library name="com.mitsubishielectric.ada.util.explog.lib"/>
<uses-library name="com.mitsubishielectric.uilib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.phonecoordination.lib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.powermanager.lib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.vehiclecoordination.lib"/>
<uses-library name="com.mitsubishielectric.ada.appservice.externaldisplay.lib"/>
</application>
</manifest>