I have been out of my Mustang since 1992 and have been driving it again starting last March. I have a 2004 Explorer and the shoulder belt portion of the seat belts in that car will restrict you if you pull the belt out too quickly or hit a large bump. The shoulder belt portion of my '88 Mustang has about zero tension no matter how you pull the belt. If you pull the belt out past a certain point it will retract, but nothing prevents the belt from being pulled out. That being said, I'm wondering how well they will protect me in an accident. Are they operating properly?