Say you sell your car to a salvage yard in Montcalm, MI. Then, what happens to it? One of the first things a salvage yard is going to do is drain your car of all its fluids. Not only are the fluids in your car hazardous, they can also be recycled. Motor oil can be reused as lubricant. Freon is very dangerous to the environment, but can be reused as a refrigerant. Likewise, antifreeze can be cleaned of contaminates, and then re-purposed to fill its original job in a different vehicle in the future.
Even an old or wrecked car can have several working parts that can be reused. Before the car is crushed, your salvage junk yard in Montcalm, MI, is going to pull various parts from your car to be re-purposed. The parts of the car that can be reused are commonly transmissions, alternators, axles and starters. Once these parts are cleaned, reconditioned, and tested, they can be attractive to customers who would rather buy used replacement parts instead of new. This also goes for non-engine components such as windshields, bumpers, hoods, and mirrors. Batteries are commonly recycled as well. The lead can be removed to make new batteries just as the plastic can be reused for new battery casings.
After the vehicle has been stripped and crushed, its metals can be recycled. It's estimated that over 18 million tons of steel is recycled from old cars annually. There are other metals - principally aluminum - that can be recycled as well.
It's a complicated process, but broken down vehicles have value. Even that old car you want to get rid of is not going to go to waste when you sell it to a salvage yard.