Abstract: The trailer including a main towing device movable by articulation and sliding, from top to bottom, from front to rear and from right to left to facilitate hitching the trailer to the back of a motor vehicle using a conventional ball-type trailer hitch in conformity with international road regulations. The towing device includes a flexible fixing device to fasten the front part of the trailer to the roof of the motor vehicle through a transverse and vertical centering device which slides from front to rear through sliding rails mounted on a roof-rack, or, as an alternative, through sliding rails mounted underneath the front part of the trailer. The combination of the devices enables rapid coupling and uncoupling of the trailer and the motor vehicle, the locking of the sliding motion of the main towing device in road-ready position being automatically performed by means of locks.