I drive a G31 530d xDrive Touring.
As soon as I fold down the rear seat, a yellow Check Control message appears in the display that the rear seat is not locked. The display remains permanently. In the car dealership (BMW dealer) it says: "This is probably normal ..."
As soon as I go to the status of the vehicle, the message is displayed as a fault. Does anyone have the same or a similar problem? Respectively, is this also the case with your station wagon?