They tend to pop up on here now and then. Or keep an eye out on eBay or breakers. Can't remember where I got mine from but don't recall them being expensive from new.
It is there, but for some reason this section doesn't seem to default in date order, give this a try: http://www.cliotrophy.co.uk/forum/forumdisplay.php/155-Wanted?sort=lastpost&order=desc
Bit of a long shot but you never know... Does anyone who lives around the Southampton area possibly have an engine hoist I could borrow for a week? Friends car has decided to eat the gearbox (non clio)
Also in the past I used some nuts and put them in the gaps between the rubber mounts with cable ties to reduce the movement of the exhaust which helped to extend the life of them.
Looks to me like the original OEM mounts have had it and not the exhaust it self. The warranty of the exhaust won't cover the rubber mounts.
In the last picture you posted, have the welds broken? Hard to tell from that picture, if they have then the warranty should cover it.
We've not got a list as such however when we come across one that is no more we update the number in the owners register found here: http://www.cliotrophy.co.uk/forumdisplay.php/148-Trophy-Owners-Register
If you come across one you are interested in, check the register to see if we have any...