To post something on topic: I don't mind symbolism in films or series (or even books), but if it is the or even just a major focus, it is far too easy for me to become annoyed by what I perceive to be the creative team or the writer doing it simply to feel smug and superior. Like a group of people telling each other in-jokes in the presence of someone deliberately left out, although as the good Bruno could attest to, I am being a hypocrite here, as I do enjoy that too, but I don't like it being done to me.
It's a fine line to walk and it is hard to explain where the breaking point is. To give an example, Mulholland Drive annoyed me to the point of disliking the film during the scene where the blue box is opened. In contrast, a while back I watched Adolescence of Utena, a film that has the two protagonists reach a car wash, with one of them entering as human and leaving it as a car. The other then gets in and drives off, being chased by a medieval style castle, leading to the final action/chase scene of the film and the ending.
The difference is, I guess, insofar as that scene with the car makes perfect sense within the film and all of its established symbolism, while opening the blue box came, appropriately I suppose, more or less out of the blue. That is not to say that Mulholland Drive defies understanding in any way. The film is, prior and after the change, a criticism of Hollywood and the way it tends to (ab)use people's hopes and dreams. There is just no point in the switch besides being intentionally confusing. It only gets worse if you're taking the scene at face value and ascribe everything that happened in the film to this point as Diane's fevered masturbatory (for those who have not seen the film, this is meant literally) fantasy that still pertains to reality as it is her way to cope with the other scene that happened in real life, which is the very beginning, albeit probably in a different manner than shown.
The scene breaks the narrative and adds nothing thematically. It serves no purpose, at least not in my opinion. Utena becoming a car did, and when you look back after the film is over, it was the only way it could have ended. Thematically, that is, they could have done any number of things. Car war perhaps a little on the nose, all in all.
Regarding the last paragraph: this is something I thought about not that long ago. I would not call myself an atheist, but agnostic does not truly fit either. I do reject the idea of the Abrahamic god, for instance, but I do not know whether or not there are beings or entities that could be considered, if not gods, then at least godlike. This rejection is not borne out of a counter-reaction to any upbringing either, it is one based on conclusions that I arrived at early on in elementary school, but it is my own, and I do not try to convince others, but I do talk about it if and when the topic comes up. It also happened far earlier than my rejection of the Christian church/organized religion. That did come later. Seems logical: it did take longer to understand the church and its role in history than it is to poke holes into what the Bible describes, especially if it is presented as the literal truth by one's teacher.