Recently I have had a rattle coming from what sounds like the exhaust on my 2005. I haven't been underneath to check since it can be difficult without proper stands or a lift. Sometimes it will only be at idle that it rattles. Other times it will be when I accelerate. I was feeling the mounts and they feel like the bushing are most of the way gone. Think that is all it might be?
Location: PA to KY ('07) to IL ('09) to MS ('10) to FL ('11)
A rattle could be anything. If it's at a specific RPM it could be exhaust or a number of other things that are activated at that particular harmonic. Get a set of Rhino ramps and start getting your hands dirty.
Like above, it really could be anything. My Mustang rattled in several different places. Before I got the exhaust hangars adjusted, it'd rattle up against the suspension and the exhaust tip cutouts. Even after, the sheer vibration rattles the license plate (as I only have the top two screws) and one of the tips has come loose, which rattles too. It could really be annnnnnything.
The '05's had a TSB for fixing rattles. The hangers on the transmission crossmembers tend to rattle over time. A fix (the tsb) is to use a worm clamp around each of those hangers to tighten them up.
I had such a nasty rattle develop on mine after about 20k miles, sounded like it was under the shifter. And this tbs fixed it.
But yeah, rattles can be from anywhere underneath.
When converting to dual exhaust I bought aftermarket hangers for the driver's side. Over time the rubber in both of those hangers has worn and the hanger rod basically sat on the bottom of the metal "square" part of the hanger. HORRIBLE rattle. Ended up making my own hanger brackets and used the isolators from AutoZone--what I should have done from the beginning because the rubber in those aftermarket hangers was pure junk. The OEM hangers are still holding up fabulously.
Not saying that is your issue, but it may be worth looking into. You'd be surprised at how much your exhaust moves around when it hits resonance. If there's less than 1/4" of clearance between any part of your exhaust/hangers and any other part I'd seriously look at it.