Yes, open carry is legal in North Las Vegas. Due to statewide preemptionof most firearm laws,nolocal laws apply.
You can download a pamphlet I madeconcerning Nevadas carry laws in this thread: http://opencarry.mywowbb.com/forum36/12253.html
It contains all of the limitations on open carry in Nevada that I am aware of.
Also, it is not illegal to carry in a car, and your local ordinances saying such are invalid and unenforceable.
A firearm can be anywhere within your car except concealed on your person (like under a jacket). A handgun can be fully loaded, but rifles and shotguns cannot have a round in thechamber. (magazines of rifles and shotgunscan be loaded and insertedthough)