If the loan is included in the bk, then you both will be affected, and this will go on both of your credit reports. Just be aware that the only way car loans are discharged in a bk is if the lender takes back the car.
Your only other options are to a) pay it off in full (doubtful I know) or b) sign a reaffirmation agreement stating that you will continue to pay the monthly payments and that you acknowledge that you still legally owe the debt.
But the credit effect will be on both of you if you don't sign one of those reaffs. But don't sign it unless it makes financial sense to do so.
