I got a call late in the day from my regional CSM, and this is how things went:
Since I stated that my clunk has disappeared, my current case has been closed. She seemed genuinely surprised at my findings, and she also said that she would pass my case results up the line in an effort to make sure that they catch the attention of the right people. As far as how much truth there was to her statements, I can't be certain, and I'll maintain my skepticism, but I'm also optimistic for the rest of you involved with this issue.
I'm still waiting to hear back from Crystal on what she's heard from body engineering or otherwise, but things have gone as far as they're gonna go with my regional CSM. My CSM did recommend that I visit the following website and submit my findings, though: http://Fordnewideas.com/
Car does still seems to be clunk free, 6 days later. Looks like I'll have some weather in the 60's next week, that'll be the real test.