Looks great TravyTrav.
Glad you were able to find a body shop that was willing to work on it for you. I had two body shops turn down the install of a Wald & MyRide replica. Fitment for both was a bit off out of the box but definitely workable...some body shops just don't like a challenge I guess. Wish we had more tuner/modder friendly shops where I live!
Used PL Premium Construction Polyurethane adhesive + 3M tape (for initial adhesion & holding) to secure the wing on. The thing is going nowhere
(and I don't plan on ever taking it off).
Used nothing but screws to secure the diffuser on: Two above each of the exhaust tips, one inside and just above where each of the exhaust tips are, and one where the skinny parts wrap under the bumper just behind the rear wheels. Recessed the screws, and WAS going to fill them in but after seeing everything installed I decided to leave them - kinda like the rivet-like look they give. Anyway, I used screws because there are harsh winters up here in Toronto, and I drive my car year round (garage parked though) so didn't want any possibility of 3M tape failing on me.
I used gunmetal Plasti Dip on the diffuser (after getting it painted Obsidian), and Tamiya PS-31 Smoke paint on the emblems (black pearl replicas
Shout out to awzdusty for selling me the diffuser on these forums! Great guy to deal with.