I hear what you are saying--but they seem to do this on other cars as well. The 335 was marketed with the 189's--I never saw anything with the non-sport wheels (see, I don't even know the style number
).
That being said, the 18's are gun-metal, right? I have never understood the appeal of this type of finish. I do understand that different peeps like different things, but they always just look dirty to me. Not much "pop" if you will.
But I do agree--BMW should have realized how things would shake out by showing the car solely with the optional 19's.