AudioService.init has no internal timeout and an unhandled onConnectionSuspended case in its MediaBrowser self-bind; under bind contention with the car's connection it can hang forever, so runApp never ran (black car screen, white phone UI until process kill). Race init against an 8s timeout without ever re-calling it: on timeout run a bootstrap app that waits on the same future, wires the handler exactly once when it resolves, reports errors via FlutterError, and swaps to the real app. Auto browse sources now register before the init await since they take no handler dependency.