A3 2003 Identify this part please
 

Hi all,
my daughters A3 has developed an annoying rattle under the exhaust.
I have identified the culprit but do not know what this part is called it sits in a under the pipe and its rattling on its brackets. Anyone know what the correct name for this part is please. Circled in the pic.



Thanks in advance for any help.

This is a catalytic converter heat shield. The older models had those to protect the catalytic converters as well as making sure they keep/reach optimal temperature.
Considering the age - most likely something rusted off. Either the nuts/screws came loose or are missing or the welding has rusted off.
I would weld it back together (might want to have a shop do it, if you don't feel comfortable) since the rust probably killed the thread which means a replacement nuts/screw will not hold anymore.

Hi,

Thanks for your comprehensive answer much appreciated.