No one allowed after they close
They have security in a patrol car at night. If the Costco is closed and you are in your vehicle, after all the shoppers have left they will ask you to leave. I'm not sure what happens to the vehicles that stay too long.
No
Default answer would be no cause I think it's on fair that way. I wouldn't want to risk anyways. There's should be plenty of other overnight parking. It doesn't have to be costco parking.
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