Auto body shops repair vehicles involved in accidents by fixing dents, changing body panels, replacing auto glass and re-spraying car bodies. They also do miscellaneous repairs to the inside of the vehicles. Some body shops are restoration specialists that rebuild vintage cars from the ground up.
When a vehicle involved in an accident is brought in for repairs, auto body shops notify the insurance company so that the damage can be assessed. Some body shops are affiliated with tow companies that do police tows. In some cases, a forensic team comes in and checks out the vehicle before anyone, including the insurance adjuster, touches it.
Once all the legal and insurance work is out of the way, and the car is deemed repairable, the body shop can go ahead with the work after consulting the owner. Minor dents are pulled out. Body parts that are too damaged are replaced. If the car needs electrical or mechanical work, it is sent to an affiliate shop. If the body shop is also a mechanical repair shop, it's done in-house.
The final step is the color matching and painting. Each auto manufacturer has a color code for each color, which is found on the vehicle's ID plate. The code provides the formula for the paint, which is either mixed manually or, more often, by a computer controlled mixer. Due to color fade, especially in cars a few years old, the auto body painter still has to eyeball the color to ensure a perfect match.