I have an 24 R and a 23 37 - the 37 had a bit of a rattle and after a couple of trips to the dealer they ultimately found the right side flapper actuator was rattling internally and so Ford replaced the entire exhaust and it remedied the rattle and it sounded much better than it had since new.
On my 24R, I have a cold start rattle, different sound than the 23 37, Ford recently replaced the center exhaust section and it still makes the exact same rattle at a cold start up. It also has a rasp under moderate to hard acceleration that I have not been able to determine if it's related to the cold start rattle.