Security doesn’t make money. They will have lost sales due to this event, but not nearly as much as they saved by skimping on security.
And they haven’t actually lost that many sales, either. If you’re going to buy a car, you’re going to buy a car. If the place is closed, you’re going to come back later. Few people are going to go to a competitor if they’ve already made their choice of brand. And even fewer are going to decide not to buy a car at all over this event.