67 Dart shoulder harness anchor?

A ragtop story:

In the early 70's stationed at NAS Miramar San Diego, I had a part time job at the base auto hobby shop. There was a pilot who was ?? taking care of his young nephew for the summer. The pilot owned about a 62 'Vette ragtop. I had not seen either for weeks, one day the much cut up nephew walked into the hobby shop. I asked "WHAT happened to YOU?"

He and his girlfriend were speeding down I-15 S of the base, flipped that ***** upside down in the median strip. If I recall I don't think either were wearing seat belts. SOMEHOW both of them lived through the upside down slide inside that ragtop roadster!!!