Another seat installation question ( aluminum ) Options

[FastFroggy]

Working my seat installation... I'm happy with the base mounts
(IMG:http://www.914world.com/bbs2/uploads_offsite/img.photobucket.com-19415-1488067033.1.jpg)
but struggling with the back support..
(IMG:http://www.914world.com/bbs2/uploads_offsite/img.photobucket.com-19415-1488067033.2.jpg)



Problem is that there really is not any space to even put your hands in let alone mark you spot.

But my basic question: which is preferred and why?

a. Should belt and seat back mount to firewall.
b. Should belt and seat back mount to roll bar ( i prefer this but I cannot figure a way to do this given the space available.).
c. Should belt to fire wall and seat back mount to roll bar.
d. Should belt to roll bar and seat back mount to firewall.

Please note that I have an eight paint roll cage.

[wndsrfr]

If you're racing you'll need to find out the rules about seat support. I'm doing DE events only & don't have the seat back supported, just the base. Belts are clipped to eye bolts through bolted to reinforcing plates welded on the back side of the firewall...so the belts hold me and the seat in place I guess.