I have a 1988 I installed this LED on, IT'S NOT OEM! I also added a modulator. The wiring goes through the trunk and under the seat, someone can give you the color code for yours. If you need more pictures just pm me.
I just added one to mine a few days ago. What I did was use prep-sol to remove the wax from the trunk lid. I then removed the rubber gaskets from the spoiler and used doubled over masking tape to hold the gaskets to the spoiler. I then used several strips of tape on the area where the spoiler will be sitting. I then positioned the spoiler where it should be. The spoiler has a slightly curved section toward the rear. You can feel how it fits snug at the rear .Then with some help position the spoiler left and right making sure you have about the same amount of distance on both sides. When you feel good about the position have your helper use a marker to trace around the gasket while you hole it in place. Remove the spoiler,place the gaskets back on the marks on the tape and mark the hole locations. I used a Rotozip to to drill my holes and used a SHARP 1/8 " bit. I was able to just open up the holes with the Rotozipthat instead of moving up to a larger bit. I was a little intimidated in the begining to start drilling holes in the trunk,but it really was pretty simple. I hope this helps.