Yes, boiling water can be used to remove potentially unwanted dents on your vehicle as long as you have a plastic bumper and you can successfully access the dent from the rear. First, you should boil water in a kettle, wear rubber gloves to avoid burns, and have a pot of cold water handy. Then pour the hot water from the kettle over the dent. Before cooling, pull the dent out from the inside. Then quickly pour cold water over the area to help it hold its shape and cure faster.