50/50 is the same as 100/0 between two cars. 50/50 is not the same as 100/0 between car and an ideal wall: an immovable barrier of practically infinite inertia

50/50 is the same as 100/0 between two cars. 50/50 is not the same as 100/0 between car and an ideal wall: an immovable barrier of practically infinite inertial mass that suffers no damage. car/car 50/50 is the same as car/ideal-barrier 50.