[Mulv]

You don't say whether your submarine belt is a 5 point or 6 point. I always have used 6 point and attach them to the floor using the seat mounting bolts and fender washers. The theory being that if the seat comes out of the car you might as well go with it and then your family will have a body to bury instead of just ashes to scatter from the massive fire in that sort of wreck.

The 5 point attachment for me was always done with a bar with holes drilled in the ends and fitted to the seat mounting bolts and mounted as above. The theory is the same as above too.... ashes blow around and can blind the other competitors.

The anti sub belt is only to hold the belts down so that you break your pelvis in a big crash rather than squashing all of your internal organs, pianos and harpsichords. It is not there to take any deceleration forces so the mount points are not required to be super robust just strong enough. That is why my method always passed tech in NASA, SCCA and FIA races that I did.

Jeff's method for avoiding "Tornado Carpet" is a good one that I have used as well. Even though both of us enjoy a good blaze (see flying seat above) one assumes that you have enough gray matter to not ignite your ride..