If you are going from a wrx spoiler to an STI one, the STI one has 12 bolts whereas the wrx has 4. Fortunately the bolts on the sti spoiler slide out, and four of them are in the same place as the holes left by the wrx one, which makes locating it a lot easier, and you don't have to fill in the old holes. Did mine the other week[]
Put some masking tape on the boot. Take out the two longer bolts that don't have holes drilled so the shorter bolts touch the masking tape when you offer up the new one. Put a dab of paint on them, offer it up again and you should have some paint left on the tape to drill your holes.Got mine from japperformance parts, and would say try to get as many bolts in the spoiler as possible. I've got two missing and Subaru say they come as part of the spoiler. Time for some ingenuity or a trip back to crawley[]