my dad had 14,000 of work done to his 2006 g35 coupe due to a full size construction van railing him pretty good. nailed him in the rear and pushed him into the car in front of him. insurance covered it (obviously) and it NEVER showed up on the carfax. he got rid of the car 2 months later, still nothing on the carfax.
lesson is just cause it goes through insurance doesnt mean it gets reported.