My kids play sports. Because of their ages, no two are on the same team. If we did not eat in the car, there would be many nights that we would not eat at all. It seems that the only times coaches know for practices are 5:30 or 6:00. It's also not uncommon to have games on Saturdays at 10:30, 12:00 and 1:00, all at different fields around town. Much as I would love to sit us all down, either at home or in a restaurant, there are times that the choice is to down a ham sandwich in the car or skip lunch altogether.
The other time I eat in the car is when I am driving alone late at night. Food and caffeine help me stay awake, and water just doesn't cut it.