This book is forever going to remind me of The Adventures of Kimmy Schmidt! (If you haven't seen it, one of the characters "fakes" a boyfriend and basically ends up describing Thrash and it called out by Kimmy who has read the BSC series when she was trapped in a bunker for many years).
I feel like this mystery would have been best left unresolved, like Ghost Cat. I liked the idea of the surfer ghost but I question how Trash would be able to surf without being noticed, even at night (he'd eventually have to come back to shore).
Haha! I just watched this Unbreakable Kimmy Schmidt episode! I noticed the book straight away and was surprised they referred to it as a sub plot.