Can anyone explain this

[407iain]

Up until today, I assumed my car had an RT4.
I updated the firmware from 8.0 to 8.2 (to help solve crappy usb mp3 playback), and suddenly I have fully functioning bluetooth.
I can connect to the car, make calls through it and recieve calls through it. I've had the car since last August and had no idea, mainly because there was no icon or menu.
Could it have been disabled for some reason or is the RT4 just an RT5 with the bluetooth disabled?
Im guessing I actually have an RT5!