For a while now my exhaust has vibrated against my rear bumper at certain RPMs (multiples of the exhaust's natural frequency I suppose) and it's getting very annoying. All I would need to do is let it hang perhaps a quarter inch lower under the body and it wouldn't do that.

I stuck my head under there and tried to stretch the rubber things that hold the hangers to the underbody but that doesn't work. How should I go about this? Do they sell those rubber things anywhere?

 

ANY exhuast shop can fix it. They do make rubber hangers to allow for a lower exhaust, you just gotta find them.