I agree with Earnie, et al on this. You should have an anti-submarine set up. 5 point, or you can go 6 point. I just changed to 6 point on my race car, and my Cobra has a 5 point. 6 point uses a plate under the seat cushion and required slits in the foam/seat cover. I fastened just the lap belt on my SPF as it had 4 point. Then again, the belts may be the least of our worries in the unlikely event...
However, we could debate which is better: to submarine under, or do a face plant into a wood/aluminum wheel.
