The secret score behind your auto insurance.(CAUTION!)

Everyone knows that if you hit another car, your auto insurer will probably raise your premiums. But you may not know this: Your premiums can shoot up much higher if you run into a new breed of credit score used by insurers, even if you have a spotless driving record and never had an at-fault car accident.

Known as credit-based insurance scores, these numbers are computed from bill-paying and loan data collected by the major credit bureaus. In recent years, the scores have become as important in determining your annual premium as your driving record and the neighborhood where you live.

An analysis by CONSUMER REPORTS found that scoring could cost many ...