New A6
 

Hi there
I have bought a used Audi A6 06 plate recently and it is equipped with an audio-only satnav that comes with a built-in satnav. Is there any way that this can be upgraded into a full 3D picture through getting a new CD or I have to take it to the main dealer and get a brand new satnav hardware all together (which would be an expensive option)
I can see from the internet that there are many upgrade CDs in the market, are they any good?