Vehicle comprising a roof, a first bar and a second bar that are each fastened to said roof via at least one support piece (5, 6, 7, 8), said two bars (2, 3) being movable between a longitudinal position in which they each extend along a longitudinal axis X of the vehicle and a transverse position in which they each extend along a transverse axis Y of the vehicle, each of the bars (2, 3) being fastened to said at least one support piece (5, 6, 7, 8) via at least one quick fastening element comprising an actuation lever, an eccentric (105, 106) and a rod terminated by a widened end piece, and the quick fastening element being able to pass from a position for locking the bar (2, 3) on the support piece (5, 6, 7, 8), in which the end piece is in abutment against a wall of said support piece (5, 6, 7, 8) and holds the bar (2, 3) against the latter (5, 6, 7, 8), to a position of unlocking following rotation of the actuation lever and in which the rod is moved by virtue of the presence of the eccentric (105, 106), such that the widened end piece is moved away from its position and frees the bar (2, 3) in terms of movement so as to allow it to be moved, each support piece (5, 6, 7, 8) having a channel and each quick fastening element passing through the bar (2, 3) and the support piece (5, 6, 7, 8) such that the rod is placed in said channel, the locked position corresponding to abutment of the widened end piece against an external wall of the support piece (5, 6, 7, 8) that delimits a first end of said channel and the unlocked position corresponding to separation of said widened end piece from said wall, characterized in that the end piece has at least two external protuberances, and in that the internal channel has at least two satellite channels, and in that, once the end piece has been taken out of the channel corresponding to the unlocked position of the quick fastening element, said quick fastening element first undergoes a rotational movement so as to place the protuberances opposite the satellite channels, and then a translational movement so as to make the end piece slide in the channel without the possibility of rotation until it comes into abutment against the second end of the internal channel. each of the bars (2, 3) being fastened to said at least one support piece (5, 6, 7, 8) via at least one quick fastening element comprising an actuation lever, an eccentric (105, 106) and a rod terminated by a widened end piece, and the quick fastening element being able to pass from a position for locking the bar (2, 3) on the support piece (5, 6, 7, 8), in which the end piece is in abutment against a wall of said support piece (5, 6, 7, 8) and holds the bar (2, 3) against the latter (5, 6, 7, 8), to a position of unlocking following rotation of the actuation lever and in which the rod is moved by virtue of the presence of the eccentric (105, 106), such that the widened end piece is moved away from its position and frees the bar (2, 3) in terms of movement so as to allow it to be moved, each support piece (5, 6, 7, 8) having a channel and each quick fastening element passing through the bar (2, 3) and the support piece (5, 6, 7, 8) such that the rod is placed in said channel, the locked position corresponding to abutment of the widened end piece against an external wall of the support piece (5, 6, 7, 8) that delimits a first end of said channel and the unlocked position corresponding to separation of said widened end piece from said wall, characterized in that the end piece has at least two external protuberances, and in that the internal channel has at least two satellite channels, and in that, once the end piece has been taken out of the channel corresponding to the unlocked position of the quick fastening element, said quick fastening element first undergoes a rotational movement so as to place the protuberances opposite the satellite channels, and then a translational movement so as to make the end piece slide in the channel without the possibility of rotation until it comes into abutment against the second end of the internal channel.