Mine is a 2010 MY with 3G MMI so it has nothing in the boot other than the stereo amplifier. The Sat Nav is the HDD based version so I'm guessing that's behind the dash somewhere in the front, so maybe it is just a straightforward aerial replacement due to some clumsy gimp damaging the originals when they tore out the rear windscreen aeons ago (which subsequently caused it to leak for 3 years!!) ...
On another note... Where is the DAB Aerial?