I have a question about cages, and mods that actually work.

I have a Spec Miata (yeah, who doesnt!) that I'd like to stiffen a bit and I have a couple ideas.

Many people add a "Petty bar" from the main hoop near the drivers head, down to the base of the leading edge of the passenger door. Good proven design, 'nuff said. But I'd like to leave space for an occasional passenger seat.

I've also seen some cages built with a diagonal bar going from the main hoop near the drivers head, over to the top of the passenger a-pillar (along the roofline). Is this method effective in adding rigidity and tosional stiffness to the cage?

Also, I'm looking for thoughts to adding another bar going from the same point on the main hoop (near drivers head), diagonally down to the right rear, attaching near the top of the shock (tied into existing support).

These two ideas together seem, in theory to be ideal...but I'm not a cage builder....

Thoughts?

Thanks,

Tom
Finger Lakes Region