Rattling Borla

My Borla only just fits, it looks and sound great but when I drive slowly on poor roads something rattles, I stuffed a couple of exhaust “O” rings between the heat shield and the muffler and I think that cured it but they keep falling out.
Does anyone know of some sort of heat proof sticky backed matting that I could stick on top of the muffler?
Or is there a better cure, is anyone else having the same problem?

You could cut some thin "slices" of rubber heater tubing like the kind the rubber tubes that carry water/coolant under the hood are made up of and create a spacer. They shouldnt give you any problems with regards to eat.

You shouldnt have the rattling problem... I dont with my Borla. Is yours bolted or welded together? If its just bolted up, loosen the exhaust, make some spacers, and insert them where the muffler is rattling at giving ample clearance. Then retighten the exhaust and remove the spacers and it ought to stay put where you tighted it.. I would give that a try.

Thanks Steve0, yep its bolted together, making spacers is a good and simple idea, I will have a go next weekend.
I spent hours putting it together and it does not fit very well, for example the bit that goes over the axel has to be as low as it can and even then it almost touches the body.
I thought I had fixed it a few a weeks ago because I found 2 screws missing from the heat shield.