Lots of the videos in the compilation were from Europe, so no, not everyone in Europe wears a seatbelt.I don't know why people don't wear their seat belts. But it's prevalent enough for Car manufacturers to have bigger air bags in the US to account for people not wearing their seatbelts. In Europe, everyone wears their seatbelt so the airbags are smaller.
Perhaps it's SRS. Truthfully, I don't know. NPR stated that it was due to seatbelts, but I can't find any supporting evidence.Lots of the videos in the compilation were from Europe, so no, not everyone in Europe wears a seatbelt.
I'd be willing to guess the airbags are smaller because the various governments don't have the same SRS requirements the US has.