My 3" system is hanging by two hangers in the rear by the muffler and the headers. No tailpipes or anything just a singe in single out super 40 dumped behind the bumper.

 

Not bad at all. Maybe a little loss in ground clearance. I never had one. My muffler dumped before axle though. A good exhaust shop can still get exhaust tucked without it or pretty close.

 

Its tucked like stock and it's solid as a rock. I'm just worried about the weight on my headers over time maybe causing stress cracks or something.

 

I didn't have one for a couple months with my flowmaster setup and eventually the pipes sagged down just after the cat and began scraping here and there. Eventually I welded together my own hanger out of random pieces of steal i had floating around the garage. I did it that way because i didn't want to tack weld the exhaust together incase I had to remove it later

 

Over time it will do exactly that. You need some support for the weight of the cat. From the headers to the over axle hanger is to long of a run to be unsupported.