Most folks just support the exhaust system at the rear of the muffler. There are some factory brackets attached to the area where the floor sweeps up behind the rear seat. The drivers side is welded in at the factory and the hipo cars with dual exhaust got a bolt in piece on the passengers side. They are available repo on ebay. By using these brackets you wont have to utilize the seat belt bolts. I think the key to keeping your hangers and exhaust from breaking is allowing it to flex and move when the motor is running. So supporting it at the front, other than by the headers themselves, will create breakage.
