Wow....what a facebook message to receive! Hmmm....he hasn't been drinking but was currently on his 3rd glass does sound a bit suspicious. I am certainly no expert but it sounds like he has relapsed and that perhaps his contact of you was fueled by alcohol.
It is hard to live through the memories of old hurts when they are things you have not thought about for a long time, I know. He is right to apologize for the pain he has caused, but I have no idea if he would be able to replace the car he stole 20 years ago. At least it may give you an opportunity for complete closure by telling him EXACTLY how you felt at that time.
However you proceed, remember that you are no longer that scared 18 yo girl. Best wishes, and huge hugs!
HG