SUV damaged in car accidentGAP (guaranteed asset protection) insurance covers the gap between how much your car is worth and the remainder of your auto loan and covers the gap. So if you get into an accident that totals your car, and the value of the car is $15,000 but you still owe $17,000 on your auto loan, GAP insurance would cover the $2,000 difference.

This article explains more, including costs, coverage and comparisons.