Car doors If any of your car doors become damaged beyond repair – either through corrosion or collision – you must replace them immediately. Even if your car door is salvageable, it is often cheaper to replace the door, rather than repair it. Car hinges Due to constant opening and shutting, the hinges of your car doors may wear out over time. If any of your doors begin to sag, the issue is likely to be because of failing hinges. You should check and replace any faulty hinges to prevent the rest of the door from wearing out much sooner than it should.