Having a problem in-car with iOS 8 - only started using Siri seriously with iOS 8 so not sure if it existed in previous versions. Scenario is, I'm listening to car radio, using Waze as a satnav. Waze breaks into the radio every so often to give directions. So far, so good. iPhone 6 is powered so if I want to send a text or make a call I can do "Hey, Siri" and interact in that way, which also cuts into the radio. But when I'm done with Siri, and she either times out or I say "Goodbye", my iPhone starts playing music from the most recent playlist rather than giving up control back to my car radio. If I call up Siri again and ask her to stop playing the music, she'll say "OK, I've paused it"... and then when she dismisses herself, the music will start again. I have to reach out and manually stop the music on my phone, which then cedes control to my car radio again. I have found the whole configuration of in-car bluetooth a huge pain, and it's so nearly working, but this is the last problem... but it's a particularly annoying one!