Dunno only just bought car and I’m a Ford man so still learning audi
If you go into the settings of it you can see version / software information - that will tell you a software code
or if you photo it im sure it can be worked out what system you have - i "think" i have seen a retrofit kit (3rd party for DAB on a certain model - im looking now to see if i bookmarked a link) but after my experience i sorta gave up with the idea and havent really ignited my interest on it again LOL
EDIT: Found link + more info:
For MMI 3G and 3G+ -
Plug & Play DAB DAB+ Digital Radio Interface Adapter for Audi MMI 3G 3G+ | eBay
For MMI 2G -
Plug & Play DAB+ Digital Radio Interface Adapter for Audi A5 8T A6 4F MMI 2G | eBay
This is where my knowledge on DAB stops, but they look like the right kit to get the job done!
FYI you can also update your firmware of the MMI, i did this a little while ago,
I got my update on a digital download from these guys,
https://mmi-firmware.com - updated via SD card done in 20mins easy (its worth checking what MMI you have they were helpful to me)
the are various suppliers for the updates as they are all basically resellers of dealers and of course the dealers themselves.
Hopefully i have been helpful, welcome to the forum! and congrats on the Audi
