Keep in mind - I leave this "as good as it gets" by Charlotte standards :)
I am BORN AND RAISED Arizona, and within the past 18 months moved to Charlotte,.. Luckily I found this gem early on in my relocation, and it is THE BEST and CLOSEST thing to "legitimate Mexican" food as I possible --- and trust me, I have SEARCHED and been disappointed. It is about a 25 minute drive from our house, but we go here every chance we can.
It is the most legitimate Mexican food (and we are often times the ONLY Caucasian people in the place, which is a good sign to us). We love the service (although can be "slow" to American standards).. you just have to ask for things.
My fiance always gets the fajitas, and I always get the pastor tacos (I tried a few others, and that is my favorite). Salsas are good, as well.
If you are looking for the CLOSEST thing to "Mexican" food (by Arizona and Mexico standards), THIS IS IT!! (even their TV's are in Spanish / Spanish soap operas)!