When i drive my mini cooper hard, and the exhaust (supersprint catback) gets a little hot and when i sit in IDLE the muffler has vibration and this vibration is sent back and absorbed by the hanger rubbers mountings ....

BUT the right hanger rubber (or what should i call it) makes this very loud and very very annoying rattle.... I double checked and the rattle is certainly coming from the mufflers steel hanger that is rubbing against the rubber mounting when there is vibration... very strange because when i move the muffler or push it a little with my hand the rattle stops, but offcourse will come back when the muffler finds its place again expands and starts to rattle again and again and again ???

what should i do... ???

thx for your very well appreciated help, i hope

 

Little bit of white lithium grease in the hanger? And check to see that the hanger is solid in it's mount.
Sorry, that's all I got.