Q. I should be nearing the end of a 60-month simple interest auto loan. The interest rate was 17%. I know that was high, but I could not avoid it at the time. The loan has never been more than 60 days late, but I'm being assessed an additional $4,000 in interest. How can that be?

A. The fact that you started out paying 17% interest tells us that you have a subprime auto loan for borrowers with bad credit. These types of loans usually have very stiff penalties for making so much as a single late payment.

When you fell behind, you probably triggered a clause in your contract that increased the interest rate to 30% or more for the duration of the loan.

That's how you would incur an extra $4,000 in interest charges.