with rubber
late 1800`s
not if the car was not originally equipped with them.
You don't install a newborn car seat. The only thing that you need to do with a newborn car seat is put the car seat in the back of the car and put the seat belts on and lock the seat belts.
Seat belts were invented early in the 1880s, but were not patented (by a different person than the inventor) until late in the 1880s.
Neither. Seat belts are generally anchored to the floor of a car.
in 1970
It is probable that no one knows this answer. Auto seat belts came into use well after seat belts had been in common usage in aircraft for decades and decades!
See History of seat belts
a seat belt for each seat
by wearing your seat belts
ford