Would the following be correct? "throwing around the passengers who chose not to wear a seatbelt."
It's a phrase, not a sentence, so its correctness depends on the sentence you put it in.
eg The driver of the car stopped very suddenly, throwing around the passengers who chose not to wear a seatbelt."
If you are thinking that 'seatbelt' should be plural, it could be but singular is OK.
Best wishes, Clive