Thanks for the reply. I bought the same kit, had them painted, and am trial fitting them for the paint protection film. Using just the screws, they do fit snugly against the fender sides, so I was thinking about skipping the trim tape, especially since the tape would make them hard to remove should that step ever be necessary.
Did you have any trouble peeling the pinstriping tape off? I was concerned about the permanence of the tape if I had to leave it on the fender for any length of time, so I went with 1/8" wide artist's tape from Hobby Lobby.