Bob,
I just sent you a personal email with a Superformance Service Tip specifically addressing this subject. Yes, there are attachment points on the frame behind the bulkhead and slits through which you can attach a belt harness. In my case I had the installer fabricate a steel piece with holes in each end to accomodate the 7/16" bolt recommended. One end is bolted to the frame and the other end extends through the bulkhead just far enough to attach the harness. This allows for the harnesses to be attached and removed if necessary without jacking the car, removing a tire etc.
I chose the 3" Corbeau harness with the camlock release.
Corbeau: 3-Inch 5-Point Harness Belts
If anyone else would like a copy of the Service Tip send a private message with your email address. It's a 500+ kbyte file that I can't seem to include or upload.