2004 Exhaust rattle, heat shields? Muffler?

[Sumner5]

2004 Yukon has rattle when in gear and slowly starting to move forward. It sound like tin shields. I went under vehicle and the shields are all tight, muffler shield on top of muffler is tight, with no cracks as far as I can tell as I ran my hand over the muffler. Any other areas to check?
Thanks

 

[605Jake123]

I would also like to know possible things to look at i have the same problem but it only happens after it warms up a little. it's really annoying!