Have a look at this thread. It can be done but it is a big job. The concert and Symphony units are basically the same so the thread still applies to yours.
https://www.audi-sport.net/xf/threads/symphony-to-mmi-3g-retrofit-done.274667/
@lee suddick , I've just re-read the thread
@EXSpartan36 posted, and it's an absolutely brilliant step-by-step guide on how to upgrade to MMI 3G+. But I stand by the comment I made in that thread; it's a lot of time, effort and money to install a system that is now more than a decade or so behind the times, and requires time-consuming and/or expensive annual map updates.
If you don't already have that system in the car, I really would not recommend retro-fitting it. Instead, I'd consider installing an Apple CarPlay/Android Auto interface, such as the one in
this link. I did that about a ten months ago, and have never regretted it. I now have a choice of Google Maps, Apple Maps or Waze, all of which are up to date all the time. Meanwhile, forget DAB, and stream your digital radio stations through your phone.
There's lots more information about installing a CarPlay/Android Auto unit in
this thread. It explores the pros and cons of buying from a UK based supplier like Unique Auto Developments (which I did) and buying direct from China via AliExpress (as
@Boundy did).