I have a Nexus 5 connected to the USB2 port, Android Auto seems to work perfectly. For the mic icon issues: Mine works fine. I'm wondering if maybe problems arise if the Bluetooth hasn't been paired? Android Auto notes: Some of my radio apps on the head unit appear to be buggy. Ex's-Pocket Casts seems to always reset my "up next" list, can't add episodes to the up next list. Forces me to select an episode and then can only navigate trough episodes within that subscriptions list. TuneIn Radio stations list cuts off after like "D's", don't have a full list of all categories or stations within a
