Basically the exhaust heat shield gets eaten away at the fixing points due to corrosion of the metal fixing nut used to secure it to the car & becomes loose, these methods basically give the fixings nuts new materials to hold up & stop the shield rattling. Now your ready & can remove the Fixing nut & clean off as much loose material that you can from the heat shield/car.

I scraped out all the iron oxide rust and the hole in the heat shield is a circle, like it has always been that size. The heat shield looks in good condition. I've got some washers that will cover it though.If you have already used method 1 & the rust bug has got hold once more or you just want to only fix the one point with minimal under the car time then this is the method for you. https://www.google.com/url?sa=t&source=web&rct=j&url=%23&ved=2ahUKEwjwvra2m7DkAhXIQUEAHdtmDGEQxa8BMAJ6BAgAEAY&usg=AOvVaw0VTJzWxrN8ZFOD4xbU2nov Just found this. The hole in heat shield is bigger. Like the heat shield has been pulled out over the remaining clip. As for fitment, I guess they just push over the screw stud that is peeping out the heat shield, and has lots of rust on its surface? Basically the 1st time you have problems you have the option to undo all the fixings of the heat shield & just push/pull the shield to one side to move it enough to give the fixing nuts something to grip onto.

Simply get your drinks can ( or other material of your choice is similar ) cut out a suitably large piece of metal that will cover the hole in the shield & also plenty of the surrounding shield too.The heat shield has two little tabs that retain the washer/clip. Bend them down slightly to remove old and fit new. the heat shield now has a big hole in it where originally it had a small hole for the retainer's stud to pass through