And here's Apple statement, disclosed int he developer kit
Message Access Profile (MAP) : iPhone 4 and later
Message Access Profile (MAP)
Message Access Profile allows exchange of messages between devices. It is mostly used for automotive hands-free use.
Note: iOS requires that the remote Bluetooth device support an encrypted connection. When establishing a pairing record between your iOS device and a Bluetooth device, you are also setting up encryption between the two devices.
Search the apple forums. Only Ford owners can't get MAP working with their cars.
What does that tell ya?