For example, I have a windows phone. In a 2012 toyota camry, the voice system DOES indeed read my text messages to me and allows me to voice command "reply" or "ignore". However, this is not a function of the camry, it's only my windows phone sending a "phone call" over bluetooth to the car. The notification that i got a text message, the voice interaction and subsequent dictation of the mesage and transcription of my reply is all Windows Phone and the camry just thinks I'm on a phone call.
Doing the same thing in my Chevy volt with MyLink so far does not work (sigh).