I don't expect, nor would I want, to take a pillion passenger for a ride on Ruby.
I had seen a few bikes with the single seat in fill and liked the look of the sexy tail, especially in red.
No way was I going to cough up nearly $300 (Australia) for the Triumph infill, which imo looks just like a tiny pillion seat, so I made my own carbon fibre in fill.
It still needs some final finishing, but I'm pretty pleased with the results.
Yes. I will modify it, eventually. It was just a quick knock up to delete the stock pillion Pad.
It turns out that a hard piece of CF is not very comfortable when you crack the throttle and have 221nm on tap.
My plan is to incorporate a pad at the front and an led light at the back, which will necessitate a reshaping to more like what you suggest.
Too busy riding Ruby, atm, to be playing in the shed.