The original owner of my car had installed the roll bar cross member for the shoulder harnesses, and I used it for a little while after purchasing the car. However, I was extremely uncomfortable with the skull-piercing eye bolts being that close to my head, so I removed the bar and installed Simpson "V" style belts.
There is a pre-cut slot under the carpet behind both seats in teh SPF cars, which gives you access to the frame cross member that runs against the back of this wall. There are also pre-pierced holes for single attachment point shoulder harnesses. You must remove the rear wheels to gain access to the cross member and the attachment holes. I also found it much easier to slit the carpet from the outside in, because the slots can be hard to find through the carpet from inside the car.
I spoke with Simpson about "Y" belts before placing my order. They told me that they will make them, but will not SFI rate them, because they are not as strong as the "V" configuration. All of their belts are made to order, so you can give them customs lengths if you like; you are not bound by what is on their website.
