Does anybody know what causes this?

So I noticed this spot on my car in January and thought it was kinda weird because I hadn't touched that spot with something hit it or anything. The spot has become a little bit bigger in these almost 3 months. I'm really confused as to what that is. I'd really appreciate if somebody knew and told me 🙏🙏 I dont know if it's clear from that picture but the spot is close to the rearview mirror and all the things that are in the top middle part of the front car like the SOS button and the inside lights.