When I was very little, we would travel to my grandparents' house for Christmas. My parents would put the back seats down in the station wagon, and pad the area with lots of blankets and put us there. We'd travel at night, so we'd sleep and not be fussy during the 6-8 hour trip (depending on where we were living). In the 60s, this was normal. Car seats weren't protective devices; they were to hold the baby and maybe let them see out the window.
And does anyone else remember car cribs? A foldable, portable high-sided cot for a baby that went on the back seat? Ours was vinyl, in a red and black plaid. It held the baby on the seat, but since it wasn't strapped in (seat belts were a luxury upgrade back then), offered no protection at all.
I have lovely memories of those Christmases. They stopped, because a) we moved too far away and b) the entire family just grew to be too big--I have over 30 first cousins on that side of the family, plus my own 6 siblings. We'd go to visit for a month every summer instead, taking turns sleeping over at various aunts and uncles houses, and my other grandparents, who had a much smaller house.