Wacky Packages appearance in the movie Detroit Rock City (1999)
Stickers, Shirts, and a full box appear in this movie.
see other film appearances
Two stickers on a locker: Beanball and another (looks like Gadzooka), at 13 minutes, 6 seconds into the movie:

Two shirts: Wormy Packages and Gadzooka, at 52 minutes, 10 seconds into the movie (they also appear at 1 hour, 19 minutes, 5 seconds):

A full box on a counter at 1 hour, 7 minutes, 22 seconds into the movie (it appears five times: 52:38, 1:06:00, 1:06:40, 1:07:13, 1:07:22)

The back of the DVD case has another picture of the locker, looks like a Wormy Packages sticker is also there

Here is a closeup of the pic on the back of the DVD case: