Where to mount 6pt Sparco Harness?

[BlackParis]

Ok...

So today I test fitted the seat brackets Byron sold me They seem to fit no problem... He said they were off in one corner???

But now I am looking at this... Where do bolt the 6point harness to? Should I drill some holes in the bracket and get some grade 8 bolts/nuts/washers? Or should I use the bolts that mount the bracket down? Or should I mount this stuff elsewhere?

I had a 4pt in my old BMW and just stuck longer bolt in the rear seat mounts and they worked fine... (but I never got in an accident to test em out)

I'm just curious I want to do this the proper safe way...

O and I already have a harness bar...