When closing my door or gate I get a little rattle aftershock from underneath. At first I thought it was the muffler but I had the girlfriend close the door while looking at the muffler - nope. It almost sounds like the license plate rattling but isn't... any ideas? I'm not overly concerned but it is a

 

...or any of the other heat shields?

 

Thanks for the replies. On the next sunny day I will get right underneath and have a closer look

 

also check the welds on the muffler and piping

 

make sure and check that your tail lights are snug

 

Probably the heat shield that used to be attached to the frame above the muffler. Mine rattles too because the shield is now just laying on the muffler. Can be annoying and loud especially when backing up for some reason. The shield was originally fastened to the frame by two studs and nuts. The shields mounting holes have rusted out to a larger diiameter than the nuts and slipped over them. I was going to try and use fender washers to re-mount the shield but it looks like to get at the studs would require removing the muffler?

 

It was the shield over the muffler. It was half up and half sitting on the muffler. A simple tap on it with my index finger made the whole thing fall and it now sits on the muffler...

at least the squeak is gone now