It’s the wall suffering the impact of the cars and when you collide them together (real life cars) you take that out of the situation.

I’m thinking the cars crashing into each other is more about conservation of momentum than Newton’s Third Law (though it’s in there).

I forgot to add (+) that 20% of the base
retail price of a new vehicle is due to
federal mandates.

Thank you, NHTSA ! Why does this governmental
unit investigate buildings that blow up?

Educational, as well as entertaining.

After further review, Bill is a wiser man. I believed the old myth; so
I am enrolling in Head Start next summer.

The yellow car, in the first picture, is the Barrocko administration
and the red is the Bushneck administration. Both were national
wrecks; both should definitely not be recycled.

Aah wrong point of impact is no different from that of the wallbecause the wall represents a responsive force equal to the force applied ie the force of the car movement.

At the point of impact, the force at that point may be X2 that of 1 single car.

In other words, mythbusters are “correct” but were looking at the wrong part. They were looking at the ‘car’ results. That is correct when looking at the impact on the car and everything that is part of it. Notably, the clay rounds in the pendulum represent damage of each “car” but not the sum individually. In that sense, they are correct.

Imagine having a person against the wall and between the 50mph moving car. The damage on the “person” is X.
Now if the car was moving at twice the speed, both the “car and pedestrian” would face twice the damage potential. BUT make it 2 cars going at twice the speed, the cars face the same damage potential as before, but the object between them faces twice the damage potential. Notably, the clay rounds were never between the pendulums and struck.

You can also think of it as 2 explosives going off. If you are between them, the effects of damage potential for an object between the 2 explosives can be double that of a single explosion.