We had the two executives take cover on the floor of the vehicle. (inc.com)
It extends from the car seat base under baby's back or head, and goes all the way to the floor of the vehicle. (thespruce.com)
A car seat foot prop, also called a load leg, is a rigid leg that extends from a car seat base or the back of a convertible car seat to the floor of the vehicle. (thespruce.com)