I have seen after effects of a real one. What can be seen can not be unseen, firefighters were picking mangled pieces of the bodies from the wreck that had to be cut first in multiple parts to access what was left of the occupants.
The first autopsy I had to assist in was of a girl, about 19, passanger in a car driven by her boyfriend. Went too fast in a curve, went straight into a tree. Around 100 km per hour. The engine pulverized her below the chest. More than 30 years ago, but will never forget!
Like I said, some things can not be unseen and will stay with you for the rest of your life. There should be pictures of aftermath of accidents like that and shown to all newly minted teen drivers. They think they are invincible and indestructible.....
Yes, and expert drivers. Only because they have "driven" in computergames and watched Fast and furious hundred times.