Very vivid, very horrifying, and the most effective commercial/representation I have ever seen of an accident and the reason that wearing a seatbelt is not optional.
Since I was 16 and started driving, I have always required people in my car to wear seatbelts. That actually meant forcing my parents to wear seatbelts: when I was young they both had stories telling me how they had survived accidents "because" they had not been wearing belts. I did not find that acceptable and now I can't even imagine modeling such behavior for my kids. I guess that goes along with not wearing bike helmets (still a bone of contention in this house as I feel if we require the kids to wear them- and we do- we need to model the behavior as well).
The United States should license this commercial and it should be required to play at least 4 times a day on every channel, hopefully the ones that 16-26 year olds watch. Perhaps even younger- the time to set behaviors is before the behavior is required to survive.
h/t Red Mike