First off IANAL. From what I know you can have your loaded firearm anywhere in your vehicle. I just recommend NOT sitting on it, just in case some overzealous cop wants to hem you up on some charges. Nevada doesn't honor your Washington cpl. So I wouldn't CC if I was you. But you can pretty much OC anywhere. Although a casino can ask you to leave. OC is allowed on the strip but you run the chance of harassed by Las Vegas' finest. :quirky
Just ask Timf343. Even though he is not a lawyer. He is about the most versed on the laws on the Nevada board.
Edit: left out a NOT. Sorry about that.