Couple of funny things I saw many years ago.
1 -we had a local discount building supply a little ways out of town that had a pretty good grade to go up leaving it to gert to county road. Man bought a pretty good size stack of the cheap paneling they sold, soft Masonite on one side and pretty side as slick as ice. Driver was getting ready to leave and manager asked if he wanted some rope to tie the paneling in, which he declined saying he was only going a couple miles down the county road and his friend was going to set on top to hold it down. All went well till they got right to the top of the grade, and the driver shifted a little hard and jerked it. The entire stack, minus the sheet of paneling on the bottom slid out5 of the truck. The bottom sheet stoped on the gravel road, and the stack slid down, then the next sheet, etc., till the last sheet with the "friend" still sitting on it stopped about 10 feet from the building. Once everything stopped moving and I saw no one was hurt I started laughing so hard I had to hang on to a roof support post at the entrance of the building to keep from falling down.
2. - Going down the road, just past a place that sold sheets of Styrofoam. Pickup passed us with sheets of Styrofoam about 5 feet higher than the top of the cab. He had a ratchet strap over the foam about 2 feet from the front, and another about 2 feet from the rear. He was in a hurry, and got up speed, and as he got faster the top sheet gave a couple of flops, and the 2 foot length in front of the first strap snapped and went flying down the road like a kite, then the second one, etc. till it got down to just below the level of the truck cab. In a couple of minutes he had spread 2 x 4 foot pieces of Styrofoam along a mile stretch of highway, and never apparently noticed.