I highly doubt a working dog specifically trained for goose control will be pooping in the fields willy nilly, and that the Department of Public Works and Parks supervisor won't clean up after their dog.

Curious, is your PCP also at Mass General Brigham? Super helpful rec, but might not be an option otherwise :/

(I was recently diagnosed by a psychologist in a different system, but they could only give me a giant list of places to try calling for a psych appointment. I instead tried calling a Mass General Brigham location that would have been very convenient for me, but the scheduling staff sounded offended I would even ask without having a PCP at MGB despite 5 of 5 psychiatrists showing as "accepting new patients" online.)

I doubt it, the timing doesn't make sense with my observations. Our car was getting progressively more dirty over the course of the week, then I got a carwash at 7 pm Thursday. Our car was still clean on Friday.

I can't find a more precise start for the Braintree fire than "late Thursday" or "Thursday night", but it wouldn't have made sense for any residue to get from Braintree to Watertown instantly, then stop completely before the fire was extinguished.

Dust makes way more sense.

Hard to see, but might be 2⁰⁰ so possibly an American bicentennial sticker from 1976?

Poking around on Google Images I could only find examples with "76", not "200", so unsure.