Good, bad or nonexistent, a customer's credit score still matters when shopping for auto insurance. But the impact isn't always equal across geographies or insurers.

That's the general finding of a new report from personal finance site WalletHub, which set out to make sense of the whole issue in its 2014 Credit Score vs. Car Insurance study. The goal, according to the report's authors, was to determine how transparent insurers are being about their use of credit score information, how big of a role the data plays in underwriting decisions, and how scores are impacting policy premiums on a state-by-state basis.

"In evaluating the importance of credit data to insurance underwriting, [we] obtained quotes from five of the largest auto insurance providers in the country for two hypothetical consumers who are identical save for the fact that one has excellent credit while the other has no credit," WalletHub wrote in its report. "This allowed us to isolate for the role of credit in insurance policy pricing, but it is important to note that the exact credit-based pricing fluctuations discussed throughout the report may not hold true for all consumers given the multitude of other factors that contribute to the insurance policies each of us are extended. In other words, the fact that credit scores impact insurance premiums to a significant extent should be the main takeaway for consumers, rather than the exact amount of the impact."