As you said Mk7 and not Mk7.5 or facelift then I take it your getting a deal on an in stock car then yes you can add car net afterwards. It costs in the region of £200 and there is no hardware, it is just a case of your dealer ordering the software key and about 20 minutes to do it.
Another question about car play, if you delete Apple maps from your iphone can you then use google maps?