A 90 minute turn around isn’t terrible. I’m actually surprised 3% managed to get it in that window. Not only do you need to accept the update, you also need to be in a position to be able to accept it.

I wonder if users had to report it, or if they get pings about failed updates (the car didn’t properly check in post update)

If they detected it themselves via the car and not users, I’d be really curious to know how many failures it took to trigger an alert before someone looked into it and halted it.