In the drivera door card pocket.
Pointed on the attached picture. Excause the messy door carsas actually was cleaning it. Only picture of the door card found.
That is a regular boot release place for them.
Thought to ha e it underneath the mmi screen, where the parking assist button is but it is unecceseadily accessible to passengers.
Still need to see if it'll fit there as there is a speaker ring right behind.
Button isn't deep but it should fit in nicely there.