GTR Spoiler Installations Question???

[the_twig_187]

Hi there

I recently purchased a GTR spoiler/wing and I had a few questions regarding the install of the wing. this question pertains to people who have done the install themselves.
(1) There is a black plastic cover that fit on the trunk lid right after the hatchback rear window glass ends. I’m not sure if this piece needs to be removed for the bottom spoiler piece, or if the bottom spoiler piece fits on top of the existing piece.

The reason I believe the existing piece should remain on the car, is that the fitment of the bottom of the spoiler isn’t exact and leaves a gap for water to seep into the trunk. But I was told by the previous owner of the spoiler that he removed the existing cover and just used the spoiler bottom.

I know this might sound very confusing but I would really appreciate anybody’s knowledge or advice

Thanks
Chris