What is the proper test for proving causation in a motor vehicle accident?

In cases alleging negligence, the proper test for proving causation is the one set out in BAJI No. 3.76 (8th ed. 1994 bound vol.): "The law defines [31 Cal.App.4th 1314] cause in its own particular way. A cause of injury, damage, loss or harm is something that is a substantial factor in bringing about an injury, damage, loss or harm." (See also Mitchell v. Gonzales (1991) 54 Cal.3d 1041, 1052-1053, 1 Cal.Rptr.2d 913, 819 P.2d 872.)