I think, that there is solution for update the maps on SD navi... (not activating navi)
I made on my Audi A6 2011 with SD card MMI Low some research and find solution (nov I have MMI 3G High, so dont ask me for trying this now)
First you have to find newest 2016 maps version SD card and backup it - if someone have it, pls post it here !!!!!!!
Then find old notebook with SD card reader and probably Windows 7 Pro. (i have it on Lenovo X1 2010-2011 year and card reader was: Ricoh SD card)
You have to have working SD card in your NAVI with old maps!
1) backup your SD Card!!!
2) try something write to your SD card - if it is possible on your card reader (i tried 6 cards readers, only on Lenovo X1 it works)
3) erase this card IE in total commander
4) write new maps to this card !!! This proces due to specific copyright protection take 1 day!!!
I put this card into navi and it should work !!!
I found, that in this SD card is not readable part (readable only in specific panasonic SD readers) so this part you cant delete and it is the reason, why it works in navi with newest data...
Hope that someone make more research and find, how to activate SD navi and new SD card without codes :-)