To Capacity

It was a rainy day yesterday, so we decided to spend the morning touring the Cape Cod Potato Chip Factory. It took about 1/2 hour to get there and when we arrived, we saw a lot of cars pulling out of the street. We drove into the parking area and saw three employees blocking the entrance to the lot. We rolled down the car window and asked where to park. They said that the tours were "full to capacity" and that we should come back tomorrow when the weather would be better and the factory empty. My son was very disappointed as he wanted us to take the tour. He drove around to the main entrance and double parked the car. He went into the factory to see how crowded it was. He came out and said that there was no one on the tour. He suggested that my husband and I go in and take the tour and then he would go in with his wife and baby. We went in and took the tour and got a free sample of chips at the end. My son and his family did the same. We were the only ones on the tour. Here is the puzzle...if the lot held 100 cars and most cars hold 4 people, there should have been 400 people on the tour. There was no one, so where were all of the people that made the factory "to capacity"?  I hope they were not turned into chips.