What are my rights to co-signing for a lost vehicle with an outstanding loan?

Here is the situation... I co-signed on a vehicle for a person who since day one has been the sole driver. He took the vehicle out of state without my permission, stopped making payments for which I have been held responsible for, then totalled the vehicle by speeding off a ramp and failed to report the accident to me. After learning of the accident +3 months later I made a claim to my gap insurance only to be denied due to lack of insurance on vehicle and claiming past the 90 days allowed from date of accident. Then when I contacted the towing company they told me the vehicle was sold at auction. No notice was ever sent to me or the bank that they had the vehicle and were going to sell if not recovered. I can not find the co-signer, last I know he is in CA where the accident took place and I am still making payments on the car that is not in my possession. What can I do? Legally? I need advice. I have learned my lesson. Will he ever be held responsible? How can I find him?