Measure and get the center of the flat part of your trunk as far back as you can go. Then mesure from all sides to mounts.
This product was great for my 2007 BMW 335i sedan. It did not come with directions, but i am going to try to include some pics that show how to assemble it and some tips on mounting.Once you have it centered and measured check where mounts holes are on the inside of the trunk. You may need some longer screws than come with the kit as well as i suggest some large washers for extra stability. I adjusted the spoiler at 0 degrees(Flat) as the downforce should be 10 to 15% greater than normal at that angle according to what i read. I can tell you that at speeds over 50 you can feel the rear end planted and it works especially well in the turns.
This Spoiler I have been looking at for a few months now and finally ordered it and I can say that it was worth ordering. I can Definitely tell a difference when I take sharp turns. Overall I love this spoiler, it’s perfect, if u have any other questions about it, my insta is nyle02
I bought the double deck spoiler and this got my Honda Accord looking like a beast. Great quality. Had to drill holes into my trunk with a drill and had to get some longer screws from home depot because the ones that came with the spoiler didn't go past through the second layer of the trunk. I used threadlockers on every screw so the bolts don't get loose. This product has great quality and gave a nice touch to my car. As far as sturdiness, the top wing shakes a bit due to wind force. It would be better if it came with a bracket to install between the top and bottom deck of the wing.
Quinton.berg 
