I'm getting a rattle from the underside of my 2004 G35x. Could it be a loose heat shield?

 

Converter covers are generally the first thing to break loose! There's only one way to find out what that dreaded rattle is, get'er on a rack up in the air and start banging. If you find it is the cover have your local muffler shop reweld it for you...Gary

 

Thanks Gary