Here is a better diagram with floyds measurements on it. Measurements are to the center of the hole. Locate & drill the inside hole first. Put an original or First Place Auto Products spoiler on with a bolt through the hole. Using the measurement from the diagram and the spoiler as a template, locate & drill the outside hole. Put a bolt through that hole also. Now that the spoiler is located, use it as a template to mark and drill the other mounting holes.

Tav

(click on the word "Attachment" above for a larger image)