The invention concerns a wiper system comprising a tubular crosspiece (20) and a motor comprising a mount (24) for fixing it on the crosspiece (20) which comprises a lower housing part (36) wherein is received at least a lower part of the section (22) fixing the crosspiece, comprising means for locking the crosspiece (20) longitudinally in rotation about its axis (A) relative to the mount (24) and comprising means for fixing the crosspiece (20) fixing section (22) in the mount (24) lower housing part (36) which include at least a clamping assembly (50, 52, 54, 56). The invention is characterised in that a fastening flange (22) co-operates with the crosspiece fixing section (22) upper part and in set between a head (51) of the clamping assembly (50, 56) and the mount (24) to ensure that the crosspiece fixing section (22) is clamped into the base of the lower housing part (36), without deforming the crosspiece (20) fixing section (22) tubular profile.