Can i fit something like this into my 2004 B6.

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Here is a picture of my car as it stands -


If i bought that Nagivation system would it simply replace the two units that are already there. There seems to be one big one at the bottom and one smaller one at the top.


Im looking to go with something like this as it has sat nav, bluetooth and i can connect my multi changer as well as keeping all of the steering wheel controls. Plus it looks much better than the standard radio which is installed atm.
Any help or advice would be appreciated.