A metal sheet with attachment points for attaching the metal sheet to a support structure has a contour cut introduced in a sheet surface of the metal sheet, wherein the contour cut extends transversely to a connection line extending between a first and a second one of the attachment points. The contour cut is positioned relative to the first attachment point such that a vibration line extending as far as the first attachment point when the contour cut is not present is interrupted by the contour cut.

A metal sheet with attachment points for attaching the metal sheet to a support structure has a contour cut introduced in a sheet surface of the metal sheet, wherein the contour cut extends transversely to a connection line extending between a first and a second one of the attachment points. The contour cut is positioned relative to the first attachment point such that a vibration line extending as far as the first attachment point when the contour cut is not present is interrupted by the contour cut.

There is provided a metal insert for a weatherstrip seal comprising: an elongate central portion having a pair of spaced-apart lateral edges and a central longitudinal axis; at least one flap extending from one of the spaced-apart lateral edges, the at least one flap being folded at an angle relative to the elongate central portion about a folding axis generally parallel to the central longitudinal axis, the at least one flap comprising a plurality of fins spaced apart to define interstitial spaces between adjacent fins, each interstitial space comprising an inner end portion located near the central longitudinal portion and a notch extending from the inner end portion towards the central longitudinal axis and beyond the folding axis. There is also provided a weatherstrip seal including the metal insert and a method for manufacturing the metal insert.