On hearing loud "clunks" from the rear end, under stressed driving conditions on Norfolk's country roads, I asked my local garage (not a Jaguar dealer) to take a look at it and they have told me that the rear sub-frame bushes are worn, Is this a common fault on XJ's, and is it likely after only 70,000 miles. Is it a big job to replace these bushes? Any comments or advice would be most welcome. Regards Nev