i have an 01 sedan and the rear end on the passenger side seems to be making a rattling noise like something is gonna fall off. When i press on the brakes the noise goes away, but when i let go you can hear it again. I've heard it on other similiar cars as well.

 

I have the exact same problem on my 01 ES
The sounds goes away when I apply the brakes, but I don't think it's coming from the brakes, rather, they just stiffen everything up.

Did you ever find out what it was?