I know this is an old thread but I am bored so i am surfing.
I shaved mine and for now I have a piece of black electric tape on the hole to keep water out.I am goign to have the body shop fill it it later. The antenna kit I got (from radio shack) came witha plug, but the plug is too big and it says "if the plug is too big, just widen the hold" but I didnt since I am filling it later.