At the risk of boring everyone, these stories remind me of my own father and my childhood.
My father had odd driving habits and was unusually thrifty. When driving, to save his brakes, he believed that, if a travel situation were developing a distance in front of him, he would not apply the brake until absolutely necessary to avoid an accident. Now, he had a 1940 Buick Roadmaster, with a large rear bench seat with an armrest that folded down. I was, at around age 3, encouraged to sit on that arm rest, straddling it like a horse, so I could see over the front seat and out the windshield. Which was great until he pulled one of his last minute braking maneuvers. Then I would go flying off the armrest, and sometimes into the front seat, and into the hard metal dashboard.
When I was older, around six, he had a 1951 Buick. We regularly were driving home from my grandparents house, a 4 hour ride, on Sunday nights, with me sleeping across the rear bench seat. Again, along would come one of his braking maneuvers, and I, still asleep, would be propelled off the rear seat, and onto the car floor.
I needed a crash helmet back then.
And I won't even mention how, when I lived on a farm, my cousins and I rode in the beds of pickup trucks, rode standing in the back of stake trucks, and even sat on the tail end of a 26 foot straight truck, legs danging off the rear, on a bumpy farm road.