In Search Of VIN for 68 GTO

I am searching for the VIN for the 1968 GTO I purchased new in that year. I have checked with the dealer where I purchased the car, the state where it was originally registered and emailed Pontiac without sucess. I am running into dead ends. Does anyone have any suggestions where I could go next. I would have thought the OEM would have had the originally warranty registration but maybe I'm not looking in the right place at GM.

Did you try contacting your insurance agent, or bank where you would have financed it? I got my VIN from my insurance agent, tracked the last registered owner through a company called US Trace....sad ending to my goat...It was stolen from the guy that I sold it to and never recovered!