http://www.cleverscampcamp.com/kids-camping-bedding-theme/
What movie is it?
The summer camp. Banned child arrives at a booth together, are called "The Bed-wetting" by rest of the camp. Tormented mercilessly. Escape from the ground, the flight of a funky-looking old car. Depressing, sad song. Late 70s, I think.
"Bless the animals and children" http://movies.yahoo.com/movie/1800037967/info