If your custom car is totaled, the insurance company will pay you out for the car and then takes ownership of the vehicle, including your aftermarket parts. To keep specific parts of a totaled custom car, speak with your claims adjuster and find out if you can remove them from the vehicle. Depending on your insurer, you may be able to keep your parts if you agree to replace them with stock parts. However, you are likely to have some money taken off the actual cash value the insurer is paying you.