collectively designated 20 known as a 34 cab over 34 configuration both the body 19 and the front portion 20 may be provided with windows 21 as is conventional fig3 shows a front elevation of the motor home or trailer unit per se with the front wall portion 22 being open and having a configuration similar to that shown in fig3 when connected together the profile of the front of the trailer unit 12 is similar to the profile of the body portion of the van unit engaged by the trailer with the underside closed portion 23 of the forwardly extending portion 20 engaging upon the roof 24 of the van unit and with the lower front wall 26 of the trailer unit having a similar configuration to the rear wall 17 of the van unit so that when connected they become integral and due to the connections therebetween which will hereinafter be described become also a rigid one piece assembly the front wall 26 of the trailer unit is also open with the opening mating with the opening at the rear of the van and may also be provided with closure means such as removable or folding doors or the like not illustrated such closure being required of course when the two units are separated as shown in fig2 however normally they may remain open so that full access is provided between the van unit and the trailer unit when coupled together as shown in fig1 means are provided to detachably connect the two units together and reference should be made firstly to fig4 and 8 the main connection between the.