Hi guys,
Thanks a lot for your support and advices.
Time to give some news of my beloved 1M.
It went to my dealership for the latest software upgrade and had the automatic window-drop deleted, same for the "key less access" for opening the doors (closing and engine start is still working though). I had to specify what they had to do because they had no clue about the problem...how surprising.
This done, I had the lock replaced, both keys replaced, door repainted (4 wheels as well, took the opportunity) and locked-up the car in the "secret garage" with the rest of the collection (with the "other" M-Coupe...Z3 S54).
I don't plan to drive the car until I have a proper GPS tracker installed, probably next spring.
Thanks again and don't forget to protect as much as possible your 1M!