If there are no papers regarding the repossession, and the police were not put on notice of the repossession, and you never received a letter of default, you should contact the police and file a stolen vehicle report. You may have a wrongful repossession claim. You may be entitled to money damages.
I handle wrongful repo cases in CT. I am licensed in NY however I am not familiar with the repo laws in NY. You need to contact a consumer attorney in NY near you.