Why dont you go to the dealer and buy some window defroster vents (The triangle ones) made for Contours/Mystiques that have manual mirrors? They have the holes for the mirror adjuster, and they look like the perfect size for the tweeters. Im thinking about doing that myself...

-Dave

2002 Cadillac Escalade - Infrared with Shale leather, fully loaded

1995 Mercury Mystique LS V6 - Moonlight Blue, Atlantis Blue cloth, fully loaded Except Leather/Sunroof