I have a new (used) 2010 Prius V with navigation system. Does the iPhone 4S Siri work with Bluetooth?
I haven't checked with the new iOS 5.1 update, but if you use Siri to dial a number, either the car or the phone "hangs up" after Siri is done, but before the number is actually dialed. So you can't use it for that, sadly. (Anybody try it with the update yet?)