License plate screws for U.S. 328?

This may seem like a silly question, but it isn't. Now that I'm about to go out and get my 328 registered, the problem is that the car came without any license plate fasteners, and the ones I've found in regular auto parts stores don't fit.

The upper two attachment points are just plain square holes in the bodywork; no grommets. The grommets I've seen on sale are all too big for the holes. I can get access to these holes on the backside by reaching behind the trunk lining.

The lower two points have white plastic grommets in them, but they seem to be threaded for small screws.

I put a call in to Ferrari of Atlanta, and they should call me tomorrow. But does anyone have any knowledge about this?

(And no, this is not an April Fool's post!)