Hi,
I have updated my stock A/B unit to FW 4120 via updating to 3800 first. It works great, now have radio text etc as per my old C unit. However my white MFD is now very basic, no media or satnav on and my MFSW has now been limited. I have yay volume control and mute. I intend to put V10 maps on today.
Help :)