The creditor had to give you credit on the account for what the creditor got in the sale of the car. But you owed what was left over. Also, the creditor in the contract likely had a provision allowing it to tack on attorney's fees, court costs, and costs of collection. And interest piles up on what you owe. The debt has existed now for at least 17 years. So even if the interest rate was very low it would have grown a lot over the years. For example, let's say you owed $10,000 back in 2002. At an interest rate of only 5% that would still mean you'd owe $23,355. If you didn't have great credit your rate could be significantly higher than that. And the effect of interest scales up fast the higher the rate. In my example, if the rate were 10% rather than 5% that initial $10,000 debt would now stand at $54,355. And in California, it appears that judgments for breach of contract where a rate of interest is specified in the contract will accrue interest at the contract rate. If the contract didn't specify a rate, the judgment interest rate is 10%. In short, after 17 years that debt can be very large indeed once you tack on the various charges and interest.