New research from the Consumer Federation of America and VantageScore Solutions reveals that the U.S. public is largely in the dark about what affects their credit scores, which weigh heavily on how much they pay to borrow. Auto buyers may have to spend as much as $5,000 more in financing costs, and homebuyers could be saddled with tens of thousands of dollars in additional costs if they have a low score -- provided that they are even eligible for financing. What many Americans fail to realize is that poor credit scores also can impact their credit card rates and vehicle insurance premiums as well as their ability to rent housing, get a cell phone, or even land a job. Many consumers who participated in the survey mistakenly agreed that age and marital status impact credit scores but were not aware that co-signing on a loan actually does. More than a third of poll respondents -- women more often than men -- believed that credit repair agencies could improve their score; however, that is rarely the case.