Take your fingernail and rub it on the window perpendicular to the scratch. If your nail catches the class noticeably then its too deep to buff out.
Even if it doesn't you're very likely to make an "over" or "under polished" section by trying to buff the glass. I somehow scratched the SHIT out of my glass taking off the "efficient dynamics" sticker from the 3rd quarter panel window on my 650. The glass expert told me that no one would ever notice it but him and me, and that if it REALLY REALLY bothers me that I should just smash the glass and take a no deductable glass coverage claim from my insurance. I didn't bother. . .
You'll forget about it in time. Can you take a picture of it? If "its too small/faint to see in a picture" you should probably just forget about it and move on. I know its the first little ding/dent/scratch on your new baby, but trust me when I say that more will follow
Moral of the story: quartz is way harder then autoglass. . . Careful cleaning with your watch!