As I started this thread I might as well add my recent experience to it. As you will see from the first post, my cat/silencer had been mounted direct to the chassis, with no bobbin, for 7 years and 9000 miles with no problem, but I was persuaded to change the solid rear mount to the rubber bobbin. Seemed logical and it did improve the noise level and it stopped the continual failing of the manifold/exhaust joint. As I said at the time, it was a 'bleeding obvious' improvement,
Well, one year on and 2,500 miles later my cat and silencer have both shaken their internals to bits and need to be replaced. So maybe it wasn't so obvious after all Luckily Jeremy (jmspec) has stepped up and saved my bacon. (It's been said before but it does no harm in repeating it, this Club and it's members are amazing)
So now I shall do what I should have done a year ago and listen to the wise old heads of Mick and Bob and mount the cat/silencer at both ends and fit a flexible joint,