I took some notes. I want to clarify I do not speak Mexican-Spanish, but these expresions sound too neutral. I am puting some examples but I would suggest finding a Mexican to add more context or juice.
1) ¡Aplastémolos como cucarachas!
This is the only expresion that I found correctly...
When doing the Sonora BoS quests where you fight Raiders, I have seen some Spanish "text above npc" be missing punctuation or not seemed to make sense. I wasn't able to screenshot them. Is there a place where I can take a look at those texts and provide feedback?