Hi all.
Jeffrey here.

“Hey, Come Back Here!” is this week’s puzzle title and the theme answers have the second word reversing the first word. Palindromes! Semordnilap! Or to put it another way, 61a [Driving moves mirrored by this puzzle’s theme answers] – U’IES (U-turns).
17a [Reason to discard a note marked “I.O.U. one Pampers”?] – DIAPER REPAID. Diapers do not seem like an idea type of currency.
27a [Thoroughbred, 550 kg., 17 hands, e.g.?] – STEED DEETS. Deets is what the kids call details. Or maybe their groovy parents say it.
41a [I.D. pin worn by St. Peter?] – GATEMAN NAMETAG.
56a [Places to soak on the John B.?] – SLOOP POOLS. Sloop John B is a Beach Boys song.
66a [Sumups in a tutorial on tile separators?] – SPACER RECAPS. When I woke up this morning, I didn’t think I’d be watching a video on tile spacers.

Canadian content:
12a [Buyer’s remorse for most Canadians?] – PST/ 14d [Purchase add-on, as 12-Across] – TAX. Provincial Sales Tax. Also acceptable: GST, HST.
1d [Song with the lyric “I’m a lot like you”] –OLD MAN. Neil Young, who is not so Young anymore.
30d [Ottawa NHLer, for short] – SEN. Senators.
9d [ID on a T4 slip] – SIN. Social Insurance Number. See last week.

Tips of the Week:
If you don’t get one of the clues that I haven’t covered, leave a comment here. Barb or I will be happy to explain it.

See you next week!