What is the test for calculating damages in a motor vehicle accident?

Under the circumstances herein delineated, it is for the trier of fact to use the evidence available in assessing damages. 'It is axiomatic that where substantial compensable injury is shown but the amount of the damage cannot be ascertained with reasonable certainty * * *, the question rests in the sound judgment and discretion of the trier of fact.' (Ojala v. Bohlin, 178 Cal.App.2d 292, at p. 304, 2 Cal.Rptr. 919, at p. 926.) It cannot be said in this case that the trial court has abused its discretion.