For a couple for weeks my 7th Generation has developed an annoying rattle when you start the car or in stop and go traffic. I knew the sound was from the exhaust as it has a distinctive noise. I kneeled down look all the rubber grommet and hangers all were in place banged the silencer with my hand nothing broken internally it has to be the cat I was dreading the twin ceramic monolith have shattered inside and it banging .. I need to get the car on a ramp to confirm what is going on. I was passing by HH and nipped in just to see our arrangements were in place for our meet and get to the bottom of this issue, we traced the culprit and luckily it not the cat. The top heat shield to the cat has rusted and the bolt holding the top and bottom heat shield have given way causing the rattling. I have never seen this on other tourer even my 2.0 one which is older but this one has rusted due to excessive heat These heat shields are pretty substantial they are double skinned and thick. I have ordered the replacement heat shields it a separate part and four bolts which hold it together It is not cheap £90.00 for rattle free car,however I won't recommend anyone removing them as the cat does get really hot and it will melt the top heat shield below the gear shift mechanism causing more damage. Hope this helps other if you encounter this issue.