Echofall, I posted earlier about mounting it to the stock grill. I am sure you have figured this out, but if you did want to flush mount the tweeters to it you would have to cut the hole large enough to fit them. Then if worst comes to worse and you blow the speakers or something goes wrong with them and you decdie to switch them up and have no tweets you are going to be left with an 1" to 1 1/2" hole in your grill.
lol, good point. I didnt think of it that way. (hand)