While I'm not disagreeing with the observations that
@ecarfan made, I realized that I tick all of those boxes when I'm long-distance traveling. So it's really not safe to assume anything.
1. Luggage. We try to keep everything out of sight whenever we leave the car. Our suitcases are either in the frunk, or in the trunk under the parcel shelf. The inside of the car is clean.
2. Bugs. At every stop, I am completely OCD about getting bugs off the front end of the car, and cleaning the windshield.
3. Not being in the car. Since I have to charge for 30 minutes, I might as well stretch my legs, go find a restroom, get Starbucks or food. In my experience, the people I see just sitting in their cars while waiting to charge are often limo drivers. The ones I've talked to, who are up and out of their cars walking somewhere else, are the owners who are on long-distance trips.
4. Being there in the morning. That's when charging is least busy, so I now get up early for long trips. Granted, I don't usually reach the first supercharger stop before 9, so 7:15 is a bit early unless I'm on the road at 5 AM.
5. CA plates. Remember that you can drive all day without ever leaving the Golden State, and lots of folks regularly make the trip to/from the L.A. area.