Consumers buy insurance because they want protection against the worst case scenario, even if they hope it'll never come to pass. One example of a typical scenario is totaling your car or losing it to theft when you owe more on it than it's actually worth.
That's why there's GAP insurance coverage. If something like that happens, GAP coverage will protect you financially by assisting you in paying that extra amount you owe. You can pay for this type of insurance plan by just adding it to your original auto bill, making your payments on this coverage seem barely noticeable.