So I've been chasing a rattle in the back of my R53. It's present over bumps, but I have also heard it over seemingly smooth roads. So far, I have:

1: replaced both rear swaybar endlinks
2: replaced rear muffler(both straps were rusted, and left side was broken)
3: found the heatshield at the back of the main pipe, to where it goes into a Y, was rusted out at the mounting points, and flapping around.

So, that brings up two questions:

1: anybody experiencing any adverse effects driving without that heatshield?(hot floor, etc)

2: Any other rears a rear rattle is common to hear from?

 

Replace the rear sway bar bushings? They would create more of a clunk than a rattle though. I wouldn't recommend going without the hear shield..it's right in front of the gas tank isn't it ?