Has anyone gotten "Hey Siri" to work? as I understand it, if your phone is plugged in (charging) you can say "Hey Siri" to start Siri. No holding the phone. Thought this would be great in the car... Make reminders, timers, ask it to text for me or pull up directions. But everytime I try it, Siri says "I'm sorry but I Can't help you. Please try again in a little while" What am I doing wrong?