Legal Question in Business Law in California

Any time the cost of repair exceeds the actual market value of the vehicle if it were repaired.

A definition of "total loss" might be found in the terms of an applicble insurance policy; if so, you'd have to go with that. Otherwise, I'd say Mr. McCormick's expression of the meaning is pretty good. If you really need something more technical and/or reliable in court, you might want to look up a case called Carson v. Mercury Insurance Co., decided by the California Court of Appeal for the 4th Appellate District (serving, inter alia, Orange County), in October, 2012. This case is currently unpublished, but can perhaps be found via its case number, which is G045795. Or, send me your e-mail address and I'll forward a copy.

California Vehicle Code section 544 defines, in part, a total loss vehicle as a vehicle that has been wrecked, destroyed, or damaged, to such an extent the insurance company considers it uneconomical to make repairs to the vehicle and the vehicle is not repaired by or for the person who owned the vehicle when the damage occurred.