Generally children learn from their parents. Now my 13 year old did scream a few weeks ago in Moab, but it was what most would say was bad. Generally the dog got thrown around a few times, but I had moved the pet barier right behind the front seats. Many dogs get scared and try to "help out" in the front seat....
My son screamed when the front tire dropped off into a hole and the truck took a strong lean. Similar to an experience Carlton had at the end of Hell's Revenge....
Todd