Have to agree that open and closing 1 acct/year (maybe even 2) will not affect your score much and dont forget that the FICO scores that all those Credit agencies use are updated several times a year.
ex; if you close an acct, your ratings will go down but its only temporary -say several months, then several months later your score will be back to normal (original score). I dont know the exact amount of time your score is affected so perhaps someone who do know for sure can post here for the rest of us .
Actually having bad habits (like constant late payments, being in debt, having too many outstanding loans etc.(Yes, having that huge car loan will have major affect) and ratio of your annual income/spending ratio (debts) are the main culprits for low FICO scores.
PT