Ouch. By my rules, if I finish with more than two errors, that's a DNF. My failure mostly came at 43A: Sporty pontiac of old (TRANSAM). See, I had gRANdAM. Those middle letters being correct threw me, and I could not for the life of me get SITSPAT - I kept on thinking it would be parsed as "something AT". Meanwhile, to compound my problems, I misread 49A: Members of familles (PERES) as "families."
By the way, just to be completely clear, a Grand Am is anything but sporty...
That's my sad tale of woe, although you also have to add in putting DIs in for DIG. Really, how did I argue myself in to thinking that sIMP meant "to hobble?"
Meanwhile, the rest of the puzzle went by very quickly indeed. I had basically finished the whole thing (incorrectly, mind you) in under 8 minutes. MALALA was a gimme at 1A, as was CANTOR at 12D. I'm of two minds about 6D: Ones not calling the shots? (ANTIVAXXERS). The answer looks great in the grid, but the clue feels just a little bit off, and the sentiment needs to go the way of bloodletting in medicine.
26A: Nick name (DORATHEEXPLORER) is very nice (Nick being short for Nickelodeon, the channel the eponymous show airs on). The fully spelled out SAINTPETERSBURG is also excellent. Other answers I appreciated include STYGIAN (how vivid!) and IGNOBLE.
CARPAINT feels made up, but okay. 10D: When to start on a course (TEETIME) seems like it could also be "tea time," right?
So I'm a little disappointed in my performance today, but I'll get over it.