After implementing a lot of the suggestions on this thread (thanks to all of those that have tried to improve this model), fill body gaps, fix the paddle shift, HOG steering & suspension rebuild, mostly implemented from the PDF file - https://bricksafe.com/files/jb70/42056-pimp-up-my-porsche/42056-1 - Porsche 911 GT3 RS.pdf thanks to jb70 for collecting all improvements into one file.
It has bugged me for a while that there is a gap on the right hand side of the model, opposite the Fuel Filler Cap on the left on the front wing. So I spent a while thinking about how this space could be filled and with 5 pieces have managed to fill the gap without causing the issues of the Wheel rubbing or the door not opening.
So here are the parts needed:
The gap where the parts will be installed:
First step:
Second step - parts joined together:
Position of panel in place:
Photo is incorrect - as pointed out by AFOL1976
View from the wheel arch, note the panel does not rub the wheel nor is it visible from outside:
Need to retake photo - as pointed out by AFOL1976
I hope that someone who has been bugged by this gap can now fill it in.