Abstract: FIGS. 3a and 3b show two side elevation views of a vehicle passenger cabin defining a passenger space wherein are featured an actuation device, generally designated 2, balancing gas springs, generally designated 65, pivoting hinge member 4, inner weather seal 50, outer weather seal 51 and draught proof brush seal 62. In view generally designated 3a, a pivoting extension member 3 is shown in the retracted position for on-road driving. In view generally designated 3b, a pivoting extension member 3 is shown in the extended position for passenger access and use.