What is the onus of proving damages in a motor vehicle accident?

In Ontario the onus is, therefore, on the plaintiff to show that the injuries sustained constitute a permanent serious disfigurement or a permanent serious impairment. In Meyer v. Bright the court said, at pp. 145-46: The onus of proving damages always rests upon the plaintiff. We can see no reason why there should be any change in that rule in one of these cases. Moreover, the injured person would be seeking to come within a statutory exception. The onus of proof usually rests upon a person seeking to bring himself or herself within a statutory exception. It is our opinion that the onus of proof rests upon the injured person to establish upon the balance of probabilities that he or she is a person entitled to one of the exceptions found in s. 266(1)(a) or (b).