I didn't find anything for your car but it works for the 5E.
You can try the coding for the 5E maybe it works for your car aswell.
However there is one important thing you need to have in order to fully use that feature and that is electrical seats (memory seats).
The memory is needed to store the correct mirror postions.
Coding:
Control unit 52
-> Long coding
-> Byte 04
-> activate Bit 2 and Bit 3
If you have a MMI you can also add a menu point to toggle mirror dipping:
Control unit 09
-> access authorization/login
-> 31347
Control unit 09
-> Adaption
-> Access control 2
-> Mirror lowering on return
-> Set value to active
-> Menu control Mirror lowering
-> Set value to active
And that's it. Tested it on a 5E and it's working fine.
I will try