I called it back and got a recording that said, in part: "...If you'd like to by placed on a do not call list for the number that called you, press one now..."
I pressed one, but the way this recording is worded tells me that this DNC list won't apply to the other hundred or so other numbers they might call from. We'll see.
Blocked it also, just for kicks, but never did discover which scamarketer it might be.
Second call today, claiming my warranty on my car is going to expire and that this is my final notice. It's bs. Don't answer it. Scammer trying to trick people.