I think an Amazon datacenter is going to have a few more people than that because it's so huge. I just looked at the satellite image of their Ashburn datacenter in Google Maps. I saw maybe like 50-ish cars.
One thing to note, as mentioned in my reply to your main comment, is that many of those cars are not owned by local jobholders in the community but rather contractors which travel to various data centers across the US as maintenance requires.