How many times have you asked the customer for the last eight of the VIN? Customer rattles off the last four of the VIN. Now in my vocabulary eight and four do not sound the same no matter what language you are speaking.
Correct the customer in a polite manner, if they get mad, so what. Record their telephone number, go to a pay phone, dial *67 plus the number in the dead of night, when they wake up ask for the last four of the VIN and hang up.