The invention concerns a process for the operation of a vehicle unit comprising a motor vehicle to which a trailer is coupled, wherein the motor vehicle is equipped with electronic systems for controlling andor regulating the operating conditions of the vehicle unit. The system includes a first conventional steering assembly for the front wheels to rotate only each of the front wheels within a respective first predetermined steering angle, each front wheel rotatable to a pre-determined first maximum value within its pre-determined angle. The printed circuit board is electrically coupled to the display module. The container may be a bottle made from plastics material and the cover may be pivotally attached to the body so that it can be moved from a first position in which access to the space is permitted to a second position in which access to the space is restricted. When the Home GMLC discovers that the currently visited PLMN does not serve the original target area, it modifies the area event to the that mobile, so that the Home GMLC will be notified when the target mobile once again enters a PLMN that serves the original target area. The new variety exhibits medium vigor with a free branching and uniform spreading habit and good foliage presentation.