Barber - welcome to the forum and thank you for your honesty
I always intended to work from the z300 kit
Its strange but the photos you see of them don't do them justice.
The rear end is a series of curves that come from the D type that formed the basis.
The rear arches are wide - about 3" over the z3 narrow body.
I have 17x10 rear wheels but I may still need a spacer to fill the arch.
I admit that due to my lack of digital photo editing skills my picture may not capture what im aiming for.
The legend that is DSG however did produce this for me
Somewhere between mine and his there is the finished idea