Originally Posted By: DWallach
I was less impressed with Ford Sync. Pairing required me to type a 6 digit PIN into the phone (*). Then, every time the car started, it somehow started up my DoubleTwist music player, even though I really would rather have been using Pandora. I'm not sure whether to blame this one on my phone or on the car for saying "hey phone, start playing.").

It's the phone I believe or maybe a diferent Sync version. My rental experience with Sync and the iPhone 4 had two differences. I didn't have to type the PIN, simply verify the PIN was identical on both the Sync dashboard and my phone. No idea how this is secure to send out the PIN though. And when it resumed, it resumed what was last playing from whatever app. I had it resume local music, streamed podcasts in the iTunes store app, and streaming shout cast radio via a 3rd party app. This seems to match the behavior when the iPhone is being told to stop or start playback via headphone control buttons.