Shoulder harness attach points?

[767Jockey]

I want to attach shoulder harnesses on both sides of my Contemporary. Problem is, I have nowhere in the trunk to structurally attach them. I don't want to use the roll bar for the driver harness, as I'm not terribly fond of how that looks, and it still keeps me scratching my head to a solution to the passenger side. I'd like the straps on both sides to pass through the bulkhead into the trunk.

The fiberglass of my bulkhead is about 1/4" thick. I know the fiberglass in and of itself would make a terrible mounting point. I was thinking about cutting two 1/4" plates of aluminum, each about 18 or so inches wide, and about 10 or so inches tall, and attaching each to the rear side of the bulkhead with strong mounting bolts, then attaching the shoulder straps to these plates, using the plates to spread the load of the harnesses across a wide area of the fiberglass bulkhead in the unfortunate event that they're needed. Any ideas here guys? What have you all done about this? The frame is not an option, as it's too far away. Would the plate method I describe work? All input is appreciated.