Can a tissue box on the rear shelve become lethal?

There's a myth which goes like this : A tissue box on the rear shelve of a car can become lethal if the car is stopped instantly from the high speed. According to Newton's first law, every object has inertia which is  the tendency of a body to resist any change in its state of motion. Here's an example, assume that you were inside of a bus that moves in constant speed, 50 mph, you would also travel in the same speed. Suddenly the bus driver saw a car stopped in front of the bus and pressed the break instantly, the bus decelerated quickly. However, at the time when the bus were decelerated, you would still travel in 50 mph. It means that when the bus stopped, you would still moving, and if you were not stopped by anything, you will go all the way through until you hit the wind shield of the bus . To decelerate and prevent yourself from rushing to the windshield, you grab the handle. When you are grabbing the handle, the force of your arm will be decelerate yourself. After knowing how the Newton's first law works, we can imagine what will happened to a tissue box placed on the rear shelve of a car that is stopped instantly. The tissue box will fly to the front seat, and it might hit the driver's head. However, our question is that if this flying tissue box contains enough kinetic energy to cause a severe damage to driver's head. To find out the truth, a group of scientists conducted the experiment, testing if the tissue box on the rear shelve can badly injure the driver. Those scientists make a car travel in 65 mph and stopped it instantly, and see how much damage can the tissue box caused on the ballistic gel at the front seat. It turns out that the tissue box didn't cause severe damage on the ballistic gel. The scientists proved that the tissue box which flies from the rear shelve will only make driver feel painful, and it doesn't hurt the driver badly. The reason is that tissue boxes are not massive enough, so they don't contain high kinetic energy even traveling in 65 mph(in the same speed, the more massive an object, the more kinetic energy it contains). Nevertheless, it doesn't mean that anything that is placed on the rear shelve will be safe. In addition to the tissue box, those scientists also place other objects that is more massive on the rear shelve of cars and conducted the same experiment. In the end, they found out that the massive objects such as bowling ball and fire extinguisher can badly hurt drivers' heads when they fly from the rear shelve in high speed. The result of this experiment is warning that we have to be careful for the object that we put on the rear shelve of cars.