If you lived here I think you would understand the brilliance of Brolin's character.
I actually have an uncle who grew up in that area, and he sounds exactly like Josh Brolin in No Country. Not just the accent, he's got the exact same voice and delivery. If you close your eyes and just listen to him, the resemblance is uncanny.
I think I could listen to your uncle tell stories for hours.
I've spent a lot of time in rural West Texas and New Mexico with my job: Odessa, Ft Stockton, Arlington, Midland, etc. I swear I've been to that exact gas station (the one with the coin flip) I've really come to appreciate that area that I live in the Northwest. Everything from the people, the towns, and even weather in this movie are spot-on what I know of that area. So I don't know if the credit goes to Cormac Mccarthy for painting such great pictures in his novel, or the Coens for rendering them so accurately.
The credit that assuredly goes to the Coens is how the weather is portrayed. Like this scene:
I don't know if they planned that scene around the weather or just got lucky that day of shooting, but either way it's stuff like this that elevates this film from very good to great.
Another great touch are the cattle guards and fences. I always found it interesting that even out there in the middle of the scrub desert there would be this gate in front of the dirty road - still pretty important to folks were the property border was.