How come Grundy?
It's not parallel to the seat. I.e The straps would have to clip on either side of the poll. Where the support bar is welded on, is the ideal position for one of the straps. What you want to make that design work, is another metal loop added on top of the main harness bar, for the harness, which would also stop them sliding along the bar.
Shitty mock up -
But Green is where the harnesses would sit at the moment,
Red is where they should sit.
As you can see, red won't fit like that because of the design.
I get it!
Is there anyway of mounting to rear strut/ shock towers? I'm looking at getting harnesses and seats but not sure where to mount harnesses