Paul - the wheel arch is now on a 35cm dimater circle from the centre of the wheel and looks about right.
Here are some pictures:
IMG_0373.jpg
IMG_0374.jpg
IMG_0375.jpg
IMG_0376.jpg
IMG_0377.jpg
Seems to me that the front of each of the rear wheels is quite a way inside the wheel arch whereas the rear is well outisde the wheel arch. I have not changed this aspect of the bodyshell and so assume this pose to be standard?
Thanks
Chris