After I converted to Corvette C-4 seats http://www.panteraplace.com/page127.htm my next upgrade was installing a pair of Toyota FJ-4 Land Cruiser seat belts. http://coolfj40.stores.yahoo.net/seatbelfj19t.html
I mounted the single inertial retract mechanism to the rear bulkhead in the stock location. I had to cut a 'window' in the stock fairing cover for the larger mechanism. I removed the rocker area retract mechanism and mounted the end of the new belt to the stock steel plate. The female receptor is on a semi rigid cable like the factory GT5S. It's mounted in the stock location with an 'L' angle. What a difference over the stock Pantera set-up.