First thing first, thanks both of you for sharing this piece of art with us. Job you've done is truly amazing one!
Now let me try and explain about this strange problem some of us have. It all depends with your bodyswap, IMO. For example, I replaced it with Stradale cause I already got GT2 on RGT, and at first look of it, no problem at all. But soon as I try to adjust my seat position and move it a bit forward, interior view simply disappears and all I can see are my hands. To be honest, I just move my position slider all the way to the left and that bug doesn't show up anymore, and I can drive F50 without any problem at all.
Hope that helps with finding a solution for this ''problem''. Good luck!