If your new car is damaged in an accident
Who repairs it, with what parts, and what it does to the car's value.
Nobody plans this, and the decisions get made quickly under pressure. They are worth thinking about once, in advance.
You choose the shop. In California the insurer may recommend a repairer, and you are not obliged to use one. The right shop for a late-model car is one certified by that manufacturer, with the equipment and procedures for its structure and its driver-assistance systems — the cameras and sensors behind the glass and in the bumpers need recalibrating after a repair, and a shop without the equipment cannot do it properly.
Ask about parts. Original manufacturer parts, aftermarket equivalents and used parts are not the same, and what your policy entitles you to is written in it. On a new car this matters both for fit and for value.
Understand diminished value: a repaired car is generally worth less than an identical unrepaired one, even when the repair is excellent, because the history follows the car. Whether you can recover that depends on the circumstances and on who was at fault.
Keep every document. The estimate, the supplements, the parts list and the final invoice are what you will need later — for the warranty, for any dispute, and for the buyer who asks what happened.