In Texas, a car insurance company can pull your credit report when determining whether to offer to insure you and what rate to charge for your coverage. They know that a person with a poor credit history is statistically more likely to be involved in a car accident.
The insurer may also consider that the way you manage your finances is a reflection of how responsible you are. A more responsible driver is considered less likely to be involved in an accident (and make a claim on his or her policy). This designation makes you less risky to insure, and means that you can get better rates for your coverage.
Not all insurance companies look at credit scores, though. Even the ones that do look at this information use it with several other factors to determine how risky you are to insure. The score is weighed along with your driving record, age and other considerations, and your previous driving record is given the most weight in the calculation.
If you are concerned about how your credit record is or may be affecting your insurance, there are things you can do to improve your numbers. Paying your bills on time will eventually help to bring your score up. Another thing you can do is to keep an eye on the amount of debt that you have relative to your available credit and try to keep your credit cards well under the limit you have been given.