You are 100% incorrect. Newton 3rd law of motion states. For every action there is an equal and opposite reaction. Two vehicles travelling at100 km in a head on will stop where they hit. A vehicle travelling at 100 km hitting stationary car will move the stationary car in the direction of travel. A vehicle travelling at 200 km hitting the stationary car will move it twice as far. Ignoring variable friction quotients.
While the force placed upon each vehicle would be equal, the respective resulting accelerations would not be equal. MASS COMES INTO PLAY! (Newton's Second Law) Where p=mv (momentum = mass x velocity).
If a Grenadier is traveling at 100 kph (27.78 meters per sec) it's momentum has a value of 75,006 kg-mps (2700 kg x 27.78 mps), whereas a Mazda Miata/MX5 also traveling 100 kph has a momentum of 30,308 kg-mps (1091 kg x 27.78 mps) (again, it's way more complicated than this, put for all intents and purposes the force is equivalent but where things end up is not). I believe in order for these two vehicles to "rebound" the same distance (which I think would essentially be a dead stop), the Miata has to be traveling around 250 kph!
Edit -I'm not a physicist but play one on TV
Second edit - from
HERE
"...Newton's third law of motion is naturally applied to collisions between two objects. In a collision between two objects, both objects experience forces that are equal in magnitude and opposite in direction. Such forces often cause one object to speed up (gain momentum) and the other object to slow down (lose momentum). According to Newton's third law, the forces on the two objects are equal in magnitude. While the forces are equal in magnitude and opposite in direction, the accelerations of the objects are not necessarily equal in magnitude. In accord with
Newton's second law of motion, the acceleration of an object is dependent upon both force and mass. Thus, if the colliding objects have unequal mass, they will have unequal accelerations as a result of the contact force that results during the collision.
Consider the collision between the club head and the golf ball in the sport of golf. When the club head of a moving golf club collides with a golf ball at rest upon a tee, the force experienced by the club head is equal to the force experienced by the golf ball. Most observers of this collision have difficulty with this concept because they perceive the high speed given to the ball as the result of the collision. They are
not observing unequal forces upon the ball and club head, but rather unequal accelerations. Both club head and ball experience equal forces, yet the ball experiences a greater acceleration due to its smaller mass. In a collision, there is a force on both objects that causes an acceleration of both objects. The forces are equal in magnitude and opposite in direction, yet the least massive object receives the greatest acceleration."
Third edit - please tell me where have a physicist (or physics teacher) here who can explain this for real. I think what I am saying is correct, but Physics 201 was 30 years ago!