There are templates showing exact wing mount measurements, I don't have them. If You buy the mounting plates that screw underneath the deck lid, it's wing holes are already drilled. You would just drill through those first, up through the deck lid, in the correct places.
I mounted my wing a little farther back from stock. I didn't like the way it looked 2/3rds back on the top. I mounted it so the rear was almost even with the back.