I think a few others asked about this as well in the main RZ thread
https://pinside.com/pinball/forum/topic/rob-zombies-spook-show-international
but don't ask me where (180 pages). The consensus was that no one put the mylar on their machine. The clear on the Spookies playfields is pretty thick. I think they have a test playfield that has had over million plays on it without any problem.