You cannot compare the thickness of an original Oldsmobile Firenza rear bumper with any other rear bumper. The original Oldsmobile Firenza rear bumper is manufactured with supreme quality raw materials like carbon fiber, ABS plastic and fiberglass. All these Oldsmobile Firenza rear bumpers are thick and strong but the Oldsmobile Firenza carbon fiber rear bumper is preferred by the consumers. The weight of the Oldsmobile Firenza carbon fiber rear bumper is lighter as compared to the other. So, if you also want to purchase one, do purchase the carbon fiber bumper. Rest, is up to you, which kind of Oldsmobile Firenza rear bumper you yearn to possess.