An object holder assembly in a vehicle that includes a floor having a metal layer and an upper face intended to support at least one object. The vehicle includes at least one trunk separator having a base able to be applied on the floor and a separating partition. The separator includes a fastening device having an active configuration in which the fastening device is able to fasten the base on the floor when a lower face of the base is in contact with the upper face of the floor and a released configuration of the separator. The separator has a control member for the fastening device, able to be actuated between a locking position, in which the control member activates the fastening device, and an unlocking position. The fastening device has a movable magnet able to cooperate with the floor in the active configuration.