Credit Cards

Can anyone on the boards tell me how much will ones credit score take a dive due to a auto repossession? Just curious to know. Will it be hard to get another auto loan after that.

Why do we have to leave a little balance on the credit card instead of having a zero balance to get a better credit score? Why do we get better credit scores if we leave a balance on a credit card instead of paying it off at the end of each month?