As a solution, I propose that we replace these glass clamps with glass clamps that are intended for straight surfaces (see photo below as an example). In addition, I would place a rubber between the glass clamp and the polyester to accommodate the curvature of the polyester. Finally, these glass clamps are also used for securing the glass plates to the side of the bus (see images below), here it would also be better to use glass clamps for straight surfaces in the future. This does not present a problem as these are placed on a metal place, it would of course be nicer to use one of the other glass clamps here.