Not a bad start, I was thinking about picking up that kit....guess not anymore.
I would add matt black to the window trims, if you hand paint it, do it carefully, take your time and use a toothpick when you get the edge.
It kind of reminds me of the top-secret cars:
Maybe go with a matt black hood and black sponsor stacks and rims. You could also use that kits white decals and give it white wheels with black accents, it might present itself as gaudy, but it can be pulled off. Black euros and sidemirrors.
Are you planning on doing the interior?
My 2 cents.