well as to secure decorative plastic aerodynamic front and rear end pieces 28 and 30 respectively at the leading and trailing ends of the component 20 the end pieces 28 and 30 effectively plug the ends of the component 20 the securing assembly 32 may also help to secure the rear end piece 30 to the outer body surface 14 while only two brackets 22 are shown in fig2 and 3 it will be appreciated that a greater or lesser number of brackets 22 could readily be incorporated into the decorative plastic component 20 if more than two brackets 22 are used then a user would be afforded a degree of adjustability in the spacing of the cross bars 18 but the overall weight of each support rail 12 would be increased just slightly referring to fig4 6 an enlarged portion of the decorative plastic component 20 is shown the decorative component 20 has a hollow interior area 34 with a cutout 36 within a lower wall portion 38 fig5 and 6 in fig6 an inside wall portion 40 of the plastic component 20 includes two circular cutouts 42 for the bracket 22 it will be appreciated that a cutout 36 and a pair of cutouts 42 will be provided for each bracket 22 so if two brackets 22 are used with one decorative component 20 then two pairs of cutouts 42 and two cutouts 36 will be provided the cutouts 36 and 42 are further provided at those predetermined positions on the decorative component.