I have both the EV and a Prius PiP.
Using STOCK Samsung Galaxy S3 (android 4.1.2), MMS works great. This bluetooth stack is built by samsung. SMS will never work. The bluetooth stack is MAP which does not support SMS.
I flashed to Cyanogenmod Android 4.2.2, which is built off Google source code, so the Bluetooth stack is the same that the Nexus uses. No support for MAP on that build. Hitting phone, there isn't even a MESSAGES button.
So yes, it works, but yes, your phone has to support it.