What is negative equity on a car?

Negative equity, often called being upside down, means you owe more on your car loan than the car is worth. It's common early in a loan, especially with little down or a long term. It becomes a problem when you want to trade in or if the car is totaled. On OffLot, the Trade-in and Sell my car pages estimate your trade equity by subtracting your loan payoff from the estimated value.