Auto insurers will contract with body shops to repair vehicles for a non-negotiated set rate that is usually less than half of what a reputable independent mechanical shop would get paid. The result is your car could be a victim of cost cutting. When you sign your contract, low hourly rates and forced rental car tabs may tempt some captive body shops to cut corners.
Original Equipment Manufacturer (O.E.M.) parts are designed to fit and perform as engineered for a specific vehicle. In most cases safety is compromised and insurers make their captive shops use generic parts because they are less money. The problem is that with cheaper parts other than the cosmetic appearance of them, the airbag deployment time is affected simply due to the cheaper makeup of these parts. Insist on OEM parts and if the shop your vehicle is at balks because of a prior arrangement with an insurance company you may want to consider moving your car to a non-captive shop.
Most late model vehicles use aluminum and ultra high strength steels that require special equipment to repair. Like the high-end cars of yesterday, more and more manufacturers parts must fit with an especially high degree of precision. Look for certifications. This will ensure that the specialized training and the necessary equipment is in place.
Insurance companies will try to entice you to go to one of their captive, network shops by promoting their lifetime warranties on the replacement parts. You have to know that using any non-OEM parts will void your factory warranty if something was affected by a substitution of a cheaper non-OEM part. After a vehicle is in an accident and parts have to be replaced, as long as OEM parts are used the warranty is not void. Most body shops will guarantee their workmanship but as far as the parts go, you are best to stick with OEM and keep your factory warranty intact.
Insurance companies will want to look at your vehicle themselves without a trained professional around. You should always choose the shop of your choice and insist the appraiser go to that shop and inspect your car with the person who is fixing it. Sometimes an insurance company will tell you that they do not do that but that is not the case. By law they have to go wherever the owner of the vehicle wants them to go. Sometimes they might say if the car is drivable we will not go to the shop. They cannot refuse to look at your car where you want them to.