except when the width of slot 14c is widened sufficiently to permit its insertion or escape from bracket sections 14a b as explained above the width of segments 14f respectively is preferably about 1 8 of an inch since the diameter of lug 20a is smaller than the one formed within and by bracket sections 14a b the former will be accommodated turnably therewithin this will allow for some back and forth swinging movements of lug 20a and consequently of flap 20 yielding to smaller objects on the road in order to prevent or stabilize any excess swinging movement of flap 20 the bifurcated portions 14a b of bracket 14 are respectively provided with a vertical downwardly extending section 14g fig2 constituting a narrow elongated passage within which an upper part of flap 20 is disposed when inserted in bracket parts 14a b the conventional type mud flaps may also be used in conjunction with my invention fig4 the converging portions 14a b of bracket means 14 are as previously explained mounted to the rear chassis of the vehicle a tubular member 20b is provided from which mounting means e g an apertured plate 20c extends the former being insertable within converging sections 14a b a conventional flap 20d is then mounted e g by being bolted bolts not shown to plate 20c one thus may utilize existing mud flap types and incorporate them in the invented assembly thereby avoiding the described drawbacks inherent.