The real TSB number for the exhaust rattle is: PI0027, doc id #2393338 if anyone is interested. It reads:
"Some customers may comment on a rattle noise from under the vehicle. This noise is mostly reported when the vehicle is cold and may go away completely when the engine is warm.
It is possible that the internal baffles may be loose in the mufflers on vehicles produced before September 15, 2009 or the resonators on vehicles built before December 1, 2009."
Voodoocat, there is a bulletin, #PI0707 doc id #2767990, that describes your noise. It calls for the replacement of the shift lever mechanism trundle. Let your dealer know, it's not a big deal to replace, the labor time is only .30 of an hour.
Hope this helps,