I wanted inertia reel seatbelts rather than racing harnesses and my original plan was to mount them in the standard position -
No matter what position I tried I couldn't work out a way of mounting them where they'd work and not risk being soaked in the wet or jammed by loose luggage behind the seats.
The curve of the cockpit corners makes it harder to fit them, and I didn't want to square the corners as I believe Dave C had problems with cracking in his. So, the simplest solution was to centre mount them and I think it adds to the quirkiness of the car.
Good luck and I hope you get them fitted where you want them.