Can someone help us with the correct parts needed to upgrade a 2009 A6 with 3G MMI to have Navigation?

Unlike the pre facelift car which would state "Navigation Not Installed", these facelift cars come up "Navigation Not Available"

It has the standard Media Drive in the glove box with 2 x SD Slots that all the facelift cars have, Colour Screen and Colour DIS and all the correct buttons. It also has DAB, AMI and Bluetooth with the roof mounted antenna.

Is there some additional module required plus antenna? Don't need it to have HDD as DVD driven would be fine.