If you repo'd a car and after the fact the customer's attorney called and notified you that the customer had filed for bankruptcy and you were required to return the vehicle do you have to return it?

Absolutely. Any creditor action including repossession cannot be taken after the filing of a BK and/or before the BK is completed and discharged. The vehicle will have to be returned to the borrower to await action by the lender such as requesting the BK stay be lifted or a reaffirmation agreement made between the lender and borrower.