Bought a 4.41 a couple of weeks ago. It's fantastic but now I want to upgrad the Sat Nav from the MKIII (V17.1 3-1/31) to a MKIV. I understand that it's a simple Plug & Play swap? I've been offered a MKIV with a part number of 6590 6 951 629-01 and would be grateful if someone could advise me if it will work in my car?