This puzzle confused me a bit. Why, for instance, did they bother to make that progression of circled letters? Is it purely for the visual interest? If so, I don't think it's worth it. And that NW corner is a jumble of oddities. HOHOHO (1A: Holiday cheer) is a nice enough clue - or would be, in December. Same with USOPEN (19A: P.G.A. event played on Father's Day). Interesting, but slightly out of season. And why clue MOMENT (22A: See 36-Across) in that upside-down way? The whole block just set me off on the wrong foot, as you can plainly see.
The puzzle is, however, almost on the right date to celebrate the sesquicentennial of HENRYFORD's birth (5D: Business titan born July 30, 1863). So, that's nice. Lot's of clues referring to other answers, and the like. It also includes nods to more modern commercial enterprises like TEXACO (20A: Company in a 2001 merger with Chevron), and Whole FOODS (45A: Whole ____). Oddly, though, a Ford rival, GMC is also mentioned (50A: GMC truck (SIERRA)).
There were some clever clues, like 105A: Polo ground? (ORIENT), 28A: Short race? (DWARVES), and 29D: Give the silent treatment? (MIME). And I liked the references to other great Americans who died in the decades immediately prior to Ford's birth. NEVERMORE (31A: Opposite of eternally) for Poe, and "55A: Molding material" for Henry CLAY.
And here's a little trivia for you– I wondered whether or not Chuck LORRE (94D: "The Big Bang Theory" co-creator Chuck) was somehow related to Peter Lorre, because that name isn't all that common, and they're both in show business. Guess what? He was born Charles Michael Levine, and changed his name for personal reasons. Peter Lorre, on the other hand, was born Lásló Löwenstein. So, in short, no. They aren't related.
p.s. Other bloggers have commented that the circles represent the literal "building" of a Model T on an assembly line, of sorts. Pretty clever, actually. I wish I hadn't been so blinded by indifference and had noticed it on my own!