I think my mother just laid the babies on the front seat! Of course, in those days mothers weren’t so helicopterish. Especially after the 4th or 5th one.
I used to stand up on the floor between the front seat and dash of an early 60’s Galaxie 500. I lived.
Yep, the baby could sleep with its head in mama’s lap and the two year old could stand up in the front seat while drinking from a glass pop bottle. While mama smoked a cigarette. Lol